There were certainly some that had to close registrations as their donation base was insufficient for the number of users trying to sign up. And others were sold to very questionable companies as they couldn't finance themselves otherwise.

But that wasn't my argument. We are talking about things that can go wrong with instances. Just because you didn't see any large instances go down in this "nice weather" period, doesn't mean they are resilient to serious shocks.

A small to medium sized instance that is basically run as a hobby by a few admins and is optimized for being cheap enough to not need donations is the much more sustainable and resilient instance.