I always laugh at such long-term forecasts. OP, you don't know what will happen to you tomorrow; you don't know what will happen in an hour, but you fantasize in the amount of 50–100 years. Do people forget that they are mortal? Why do you care? Anything can happen in a hundred years, even something you cannot imagine today because new discoveries will be made after your death. Therefore, go down to earthly life and live, save your bitcoins today, and leave the future to your generations; they will figure out what to do with it.

Great advice, better think about a retirement plan to hold some bitcoins from now on, at least having 1 BTC is good enough for the long term and as a retirement fund. 50-100 years is the task of the next generation and Bitcoin will certainly remain bitcoin, if the younger generation only does a fork then bitcoin will remain above as the irreplaceable king. in the future we will never know what will happen, so just focus on what to do now.

It's not easy but if we really have the intention to collect bitcoins, we will try hard to do it because we know the great potential of bitcoins in the future. And if we have bought them and collected more bitcoins, we have to be patient if the price hasn't been able to increase because we also don't know when the price will increase. And as long as we see that the price is still low, we can use it to buy more bitcoins. But it will depend on how we manage the money we will use to buy bitcoins.

Oh my friend, why do you make predictions so far from reality? All of us here won't be able to live another 100 years so there's no point in discussing events in the next 100 years. Work hard to earn bitcoins now and just hold it for the next 10 years, you can get big profits even become rich.

Overall it won't work. It's already proven by recent Bitcoin forks and the goal is almost similar to every forked from Bitcoin or even from any other altcoins.
Some are just pure hype. This is the power of open-source or decentralization, you can just fork it or copy it just every project in cryptocurrency right now, Bitcoin to be specific but it's really different the different one. Bitcoin already proven it.

Just let them be if they want to fork it. The main version of BTC will still run normally and won't be affected by the fork coins, same with what happened before on BCH, BSV, BTG and others. They can get the fork coins at a cheap price but it won't be the same with the original Bitcoin. They can spread the word fork coins but I doubt it can pump as much as Bitcoin.

Old Bitcoiners have lots of BTC in their purse but they can be able to inherit it on their loved ones if they are too old already so it's always possible for the newer generations to own 1 BTC or more. Other than that, I think BTC can also dump hard so they can buy BTC cheaply as well.

I think people in the future will be smarter than we now as education will be more advanced by then. With that smartness they would see other forks that occurred previously to have all die and see no reason to create a new altcoins into existence. Instead they would work on Bitcoin to improve it further. What Bitcoin needs is constant innovation.
Innovation like how the segwit address was developed and introduction of lightening network to all help in faster transaction. Forking of Bitcoin is never a good idea as that just create another altcoins for whales and scammers to manipulate to steal the real Bitcoin.
At first it'll seem like the newly created forked coin will be a good investment choice but as the market mature you'll realized it was a bad investment options from the get go.

It is difficult to know what the motive of people will be 50-100 years from now, i don't even think it makes sense for us to speculate on it, but whatever happens they cannot start BTC over again, they can only fork a new coin from it, or just create an altcoin, but that does not make what they have done BTC, even if they decide to call it BTC or make BTC a part of its name.

In the next 50-100 years it is possible that another person may create another unique coin that will be mass adopted, it is not going to affect BTC or change anything for the BTC network, as a matter of fact the reason why it seems BTC users don't like altcoins is because most of them are scams and bad, any new altcoin that is good right now will be appreciated and adopted. So if the next generations can create something good and unique, it will be a good development and competition in the industry for them.

Basically all the alt coins are forks of bitcoin trying exactly what you described. They want to participate in the beginning of a coin, to be able to benefit financially of it. The problem is that they then always cash out their coins and therefore the value crashes a lot, which leaves a lot of later adoptors with a loss.