I agree with you. It wouldn't matter whether you spend your Bitcoin directly on whatever you wanted to pay for or you decide to convert to cash and still spend it as fiat, either way, you are still spending it. I don't think this kind of sentiment should be attached to Bitcoin spending because we however know that you cannot hold them forever you still have to spend them one way or the other.

They invest in Bitcoin because of the profit and they will still use the profit to buy or pay something. This isn't different than using Bitcoin directly. They can in fact save time and fees if they do it than converting their Bitcoins first. When they convert or sell their Bitcoins, the same doubt can still be experienced if one is overthinking that what if it became really expensive one day?

If BTC became a replacement to fiat, these people won't have a choice anymore to use their Bitcoin but I doubt it will happen. BTC isn't that good in the eyes of the government/banks and there are many things that could go wrong if there are no more local currencies.

I can understand the emotions that arise when spending Bitcoin directly. However, it is important to remember that Bitcoin is meant for peer-to-peer transactions and can be used whenever needed. At times, I sell Bitcoin to meet my needs when there are no other options available. This is not a bad thing as it helps me in my daily life. However, I always try to avoid making large purchases as I do not want to lose a significant portion of my Bitcoin portfolio. For smaller transactions, using Bitcoin does not matter to me, and I certainly make use of it.

With this mentality, I don't think you will ever have to sell your coin and I basically think the right idea is that, it is ok to sell ones coin if there is a profit on it and what really matter s is that we're not making loss but profit rather and one of the major reason I don't feel ok selling my BTC is the transaction fee and thank God for lightening network, except that, I don't see any reasons to make payments using Bitcoin for transactions.
I also agree with OP as I also have to swap my BTC to usdt before making payments or sending crypto just to cut cost on fees.

Don't feel any guilt when you're spending it on something important. Money is made to be spent and just like bitcoin. But it's different this time on bitcoin because we can use it as an investment. The time will come when we have to spend or sell our bitcoins and that's okay. As long as you're mind is telling you that you've got the thing you desire in exchange for it for your satisfaction then that's good. It's inevitable that the time will come when we need to spend bitcoin and that's the actual use case of it for buying things and paying for them. Before I felt bad because I'm seeing it as an investment but until I realize that it was okay and that I'm helping the ecosystem of it through spending and using it, it made me relief.

You should consider what is your goal and why you are holding or storing or accumulating Bitcoins.
If you buy some Bitcoins and spend them in your daily lives, then don't mind how much is the price of the Bitcoin on the time you spend them on your daily activities.
I think that's why it seems you are disappointed about the pizza guy before because instead of spending those Bitcoins he should have held. No one knows where Bitcoin will go before.

Paying with bitcoin is not bad, you only need to be calculative on the kind of products you're paying for that may or may not required huge units of bitcoins. Personally I can if what am buying is small so that I won't feel regrets when the price finally goes up.

But so people may decides not to use bitcoins to buy anything because they feels that's more of their future investment and it will look like transferring your future to someone else. Is some worth personal

Since 2015 Or 2016 Actually I Have Many More Bitcoin But At The Time I Don,t Understanding About Bitcoin Properly When 1 Bitcoin $750 And Maximum 1 BITCOIN $800 Than I Din,t Know How It’s Working In Future Bitcoin But Today Upsetting Like Not Hold And Crying Now Like This Than Felling Veey Bad For Paying With BTC.

You are selling your BTC in order to obtain stablecoin, right? So if you are paying with BTC, what't the different?
If you are holding for a long time and faced a bear market as we are facing now, then I think you have the right to feel bad for it. Although, if you are in need of money and you can't obtain it without converting your BTC or paying with it, then I guess there's not much to say about it. All I can say is, DCA after you used your BTC. Try to regain your former amount by trading or investing at DIP.
Another thing is that, you need to keep one portion of your holdings separately just for payments. Think of it like fiat money. If you hold fiat money, it doesn't increase in value. Or, as you said already in the OP, keep them converted into stablecoins.