What's really required is to build a community large enough that the 0.1% of people who can run it are big enough to have a group in charge, set up a foundation etc etc. It's just like going from a monarchy to a democracy, hard, takes ages, fails a lot.

That won't work for most small projects though, so orgs like https://sfconservancy.org/ exist.

Not sure what other options like SFC exist, and the differences between them though.

At a minimum you'd want them to be in charge, and fire the current lead developer if they go rogue.