The DCA strategy for all investors that wants to accumulate Bitcoin and for hodl for long it's both for new investor and also old investors, that it is also called the DCA strategy doesn't mean it must be with small fixed amount of discretionary income it depends on the financial income of such person as you keep investing the more you keep learning more about Bitcoin, the DCA is a strategy of accumulating Bitcoin and not a way of learning about Bitcoin.

DCA strategy is for all invetsors of different financial status or level whether you're a newbie or OG, you can actually invest in Bitcoin using the DCA method, there something we need to understanding, even buying very big can at some point decide to buy gradually although why the DCA method is suggested for newbies or will I call them beginners is that some newbies may not have the knowledge that they can actually invest in Bitcoin with just their discreationary income at first, some of them thinks that it has to be with huge amount but one they get the knowledge that they can do their DCA with what they have as their discreationary income, they get relieved from what they had in mind earlier.

Any of us who are considering starting to invest in bitcoin have to figure out the extent to which we have discretionary funds so that we are able to invest in bitcoin, and then we have to consider the extent to which we already have back up funds. If we are not sure about our back up funds level based on the chaos of our income/expenses and/or maybe some debts that we have, then we likely need to figure out that stuff so that we can be sure that we are investing from our discretionary funds and not money that we need for our expenses.

Is backup funds really meant for emergency? I doubt, Emergency funds is different from backup funds and shouldn't be classified as one.
But you’re right about discretionary income alone not been able to make a perfect investment, because if for instant a financial crises occurs, your discretionary income which you would have already invested into Bitcoin, shouldn’t be tempered with to meet that financial crisis. Your emergency funds is meant to.

we need to make sure we have enough funds set aside for both investments and other expenses.

Emergency fund is part of a backup funds. Back funds comprises of your emergency fund, reserve fund . This funds are not the same thing but they both share a common goal which is to protect your bitcoin investment from any real life emergencies. Whether you like it or not if you don't build your emergency fund and reserve fund you will likely sell your bitcoin investment when face any emergency situation. An emergency fund and reserve fund stands as a safety net for your bitcoin investment, having an emergency fund and reserve fund  is important because without having them to protect your bitcoin investment you will likely sell some or all of your bitcoin investment sooner or later when face with real life emergencies.

DCA is not necessarily boring, especially if you ongoingly work on your cashflows and figure out ways to increase your aggressiveness.

There could be some "boring" aspect in terms of not needing to give much if any emphasis to bitcoin prices, so for example, maybe a guy has a plan to try to prioritize bitcoin investing, and even though on average he is investing around $100 per week bitcoin, yet some weeks he is able to invest close to $300 into bitcoin (based on his cashflows that week) and other weeks, he is only able to invest around $40 or $50.. even though he might have had set up some side funds so that no matter what he buys $40 per week, and another thing that he did is to set his buys to happen anywhere between Friday and the following Thursday.  He tends to get paid on Fridays.. and so he will sometimes strategize his buys within the week (at least when he has time, since some weeks he has several activities on his schedule and he might not have time to manually make his weekly buys).. so if he has a plan that if by Thursday at 8pm, he had not made his weekly buy, he will buy at any price at that time, since on Friday, he will have a new paycheck that comes available.

Maybe he had been carrying out his plans for 6 months, and he has been also building his cashflow management, which is another thing that he considers to be interesting about his carrying out of his cashflow management for the purpose of freeing up more discretionary funds, if he is able to figure out some ways to do it.

It seems to be true that for some guys, perhaps especially traders, that the ONLY way for excitement (or a lack of boredom) for them is to be constantly having to monitor bitcoin prices so that every once in a while (depending on how active they are trying to be) trades can be made in order to potentially increase the profitability of their coins (by lowering the buy costs) or by shaving off some dollars (that they were able to scalp without any costs. 

Even if we might recognize that there can be some fun in regards to buying and selling and trying to either skim off some extra dollars or to lower the costs per BTC (including the idea of stacking more BTC for the same amount of dollars invested), the use of our time in these kinds of attempts might not be as greatly used as we might consider the fun to be.. and it seems that playing around with the price to try to get more dollars and/or bitcoin might not be as much of a great use of our time as we are perceiving it to be. 

I understand that sometimes guys can find planning and keeping track of the bitcoin and even projecting future cashflows, future BTC accumulated and future cash accumulated to be somewhat uninteresting as compared with the titillation of trying to trade and to skim off some dollars/bitcoin for free, yet it also seems to me that there can still be ways to help to make keeping track of bitcoin/cash holdings and projecting the future and then later comparing future results to projections as ways of being interesting and fun... and perhaps even to be more stress free in terms of ways to recognize and appreciate ongoing growth that likely comes from investing in terms of the up and down possibilities (and stress) that comes from trading... and yeah, guys might even consider that even if they have considerable down possibilities, there are ways to structure their various trades that if they "hit the jackpot" every once in a while, then the one win will make up for the various times that they had lost - which truly seems like a gambler's fallacy and also likely outcomes of gambler fallacies too, especially with an asset like bitcoin that we should be able to look at historical charts and see that guys who had errored on the side of building and HODLing of their coins, they had ended up with considerable profits, yet guys who had been trading, they had been continuing putting at risk the various profits that their bitcoin holdings were building up when they would sell with an expectation to be able to buy back cheaper and ongoingly putting themselves into a waiting posture rather than a posture in which they would be ongoingly, persistently, regularly, consistently and perhaps even aggressively buying bitcoin (during times that their various back up funds were otherwise strong). 

So, maybe there can be differences in regards to what guys perceive as fun (not boring)?  I will surely admit that with something like bitcoin, there have been so many times that historically, bitcoiners had gone through periods in which their ongoing building of their bitcoin holdings were not showing progress in terms of dollars, and sure maybe they were building the quantity of their bitcoin and maybe they were even making sure that they always had cash on hand and their levels of stress in regards to ongoing available cash were becoming fewer and fewer because they were getting better and better at their cashflow management and not stressing themselves out into cash shortfalls, as had been the case when they might have had been trading and/or during times prior to their having had learned how to make sure that they were reasonably and ongoingly stacking bitcoin within personally acceptable boundaries.

There are likely a lot of ways to try to establish excitement in our lives, including figuring out ways to try to increase our discretionary funds and/or decrease our expenses, so that we will feel comfortable to keep on building our bitcoin stack size every single week, even if some weeks the dollar value of that stash seems to be dropping way more than the amount of new cash we are putting in and when our new cash put into bitcoin  does not seem to be growing our bitcoin stash by large amounts, and maybe some weeks we are only adding 10k satoshis or some other modest bitcoin quantity, yet we can look back any records that we are trying to keep and we can see that our satoshis are ongoingly growing, every single week (or every single month if we are keeping track in that kind of a way).  So sometimes there can be excitement in both taking various actions, but also ongoingly monitoring the progress in the actions that we had been taking, and surely if we have a period of 2-3 years that we had generated weekly and/or monthly data, we can experience some excitement in seeing how the various data points evolve and even having some other cross comparisons of our historical records to remember where we were at during various historical points and to see the progress over decently long periods of time that likely becomes even more exciting once we get through a whole cycle or through a cycle and a half and we can see that we had kept stacking the whole time.. and maybe even trying to learn from what we did or did not do at various points in our stacking and if we might have had been able to handle the situation better, since we know that at the time we were going through various BTC price points and various BTC stacking points, we did not really know the future at that point in time, except maybe having expectations that at some point in the future the bitcoin price would go up, and we might be able to recognize and appreciate our own resilience (as not being boring) to go through those various difficult periods in our bitcoin accumulation journey.

For example, right now, there could be guys who had been investing in bitcoin for right around 3 years, and they might be feeling questionable levels of progress in their own bitcoin holdings, and maybe they came to bitcoin in early to mid 2023, and they decided to buy $100 per week in bitcoin and to simultaneously shore up their back up funds, so that maybe in the 3 years, they ended up putting around $16k into bitcoin, and they had accumulated around 0.3 BTC.  Let's say that their monthly expenses are right around $1,500 per month, and perhaps in the past 3 years, they had built up their back up funds from around 3 weeks of their expenses (maybe starting at $1k), and right now they have right around 3.5 months of their expenses (right around $5,500) in various kinds of cash-related funds in which some of the funds are more liquid (such as in local cash) and other funds might take a week or two to access, and so they are in a way better financial/psychological position based on where they are at, and maybe they had been controlling their spending through that whole time, too... so they were still able to spend on consumable goods, yet they were purposefully living in a way that they were not being wasteful with their money..and yeah, guys might consider some aspects to be boring and less exciting, since maybe they see their peers (guys with similar income levels) to be spending in ways that are much more luxurious, so the information about their prosperity or if they have been doing the right thing to be building their bitcoin and strengthening their cashflows.

It could be that such a guy is still really early in his bitcoin accumulation journey, and he may consider that it may well take him more than 10 more years to continue to accumulate bitcoin, and he might be trying to consider if there might be ways for him to increase his discretionary income and he is not sure if he will ever build up to one whole BTC, even though he believes that he is not likely going to even going to need a whole bitcoin, especially if he is considering t10-15 years from now, he may well be in a pretty good position even if he is ONLY able to accumulate somewhere between 0.5 BTC and 0.7 BTC by that time, yet he is not very sure about these future targets and he is largely just accumulating bitcoin within his own means and continuing to try to keep his bitcoin accumulation as interesting and fun.. and even with his current bitcoin stash size, he had been spending some time learning the various ways to keep his accumulated bitcoin secure... and maybe he ONLY moves bitcoin from the exchange (if he is buying on exchanges) to his private wallet every few months.... but he wants to get the bitcoin amount (or the dollar value of the amount) up to a certain threshold level before he moves those coins to a private wallet.  He might even be trying to learn lightning network and/or various ways to have some of his wallets as hot wallets, some as medium wallets and some as cold wallets, so he might be considering ways to manage his wallets and to try to preserve both security and privacy. These are not boring things to learn and to practice... so for example, if he is ongoingly looking out for opportunities that he might be able to spend his bitcoin, yet he already knows that since he is in his early bitcoin accumulation phases that if he spends any of his bitcoin, then he will likely try to make sure to buy back at least 10% to 20% more bitcoin than the amount that he spent... and those are his personal goals to try to make his bitcoin accumulation interesting (and not boring).

This is the reason why they said that if we come to investments we should invest the amounts of money that we can able to afford to lose, because a person who is plan to hold for a long period of time will not carry all the money he/she have to invest without any backup like emergency funds as you stated earlier.

That’s why it’s good for every investors to have steady income so that once they invest they won’t be thinking otherwise about the investments or financial insecurity, and because of the unexpected dangers that will come our way during holding; which is why is very important for each an every investors to be vigilant.