But "just buy it all up" doesn't actually work, even though it sounds somewhat simple. Because it implies, that everyone (people) who currently is also buying BTC would need to stop. But why would they stop if their goal is to "buy it to save for retirement in 30 years"? Or why would people who speculate on rising price in 10 years stop buying now, unless they see the price rise to say $ 100.000.000 and think "oh, now's actually a good time to sell, I've reached my goals"? In which case buying all BTC has become too expensive even for the FED.

I think the beauty is the tech can be forked and is open source. That means even if someone owns it all, anyone can duplicate it and send it out into the wild. Sure it wont have the same network power and fiat value but if no btc is circulating, a duplication at least could re-establish a circulating supply among plebs. Obviously at this point the project failed and its not ideal but at least options for self sovereignty will always remain now that the option exists.