BTC won’t vanish but most all other ones will revert to their natural state outside of the last few years bubble (zero-ish). I’m sure BTC will still be worth some thousands. And I’m a BTC long term skeptic
I actually think it would be good for people to see crypto as worthless. Maybe then they would spend it instead of holding it and it could actually act as a currency.
Why? Do you want to buy?
It's effectively one group of greedy people feeding off people that are greedy too but a bit later to the musical chairs game. And so they end up without chairs, but if you start such a game you already know that somebody is going to end up without a chair, you just hope it won't be you.