I'm not sure you fully grasped what was said in the parent comment. It literally does not matter anymore if we can all agree on the previous blocks, it would be impossible to identify who owns which wallet anymore. The seed phrase would be useless.

Ah, then yeah, in that case, it'd be basically over.

Maybe large exchanges would try to step in to make a fresh chain based on their combined account data, and just drop the people relying on self-custody. But I doubt the market would go for it - the uncertainty would crash it hard enough that it would never recover.