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.
This is true, plus that's just Europe and not the whole world. As someone who doesn't live in Europe, I do not care about what their laws about crypto is at all. To say that "crypto as we know it would be gone" requires the whole world to jump in on this, not just Europe. There are like 5 billion people give or take that doesn't really get impacted about this at all, nobody cares about this in that part of the world.
Only the European continent and the places that gets impacted by this would care about it. Which means that at the very very worst case (and not even that) it would only cause a "crypto as we know it would be gone in EUROPE" and that's it, nothing more than that.