Weird, I've had the opposite experience with Proton - I was able to recover an account with insufficient recovery info after having forgotten the password (100% my fault) after a quite thororough process. I've also completely lost access to a Google account on which I hadn't provided recovery info and my only "fault" was trying to log in from a new location (even in the same browser) - I moved places in between, so I couln't just go back to the old location.

I'm sorry this happened to you, but I find it weird that you make this out to be a problem specific to Proton. It happens to people on all major services, it sometimes even makes the front of HN. Do we have any evidence that this happens at a significantly higher rate at Proton than at other providers?