If that goes through and gets implemented, it's pretty much the end of crypto and many fundamentals it's based on such as 'not-my-keys-not-my-coins'
No, it's not.
The foundations of cryptocurrency, as an idea, are very strong. It is well known that peer-to-peer, decentralized networks are unstoppable. Of course and they can be regulated, but there's a limit. If you deposit your coins to big, centralized exchanges you fall back on the central point of failure. Don't. Use a DEX. You'll always be able to move them across pockets without anyone's permission.
I know no fundamentals that include the transition from crypto to fiat currency.
This is what's going to get harder to do.