"A clear lesson from the early days of bitcoin is that regular users suck at managing private keys."
They do indeed. And speaking as user, I don’t want to get better and managing private keys. I want someone else to do it, preferably someone who has some experience of this sort of thing, someone who has issued millions of keys and had to manage them, and ideally someone who is heavily regulated so that I have some expectation of redress in the event of a problem. Such would be a significant “incentive function” of banks if they can get their act together to do it.