On a point 5, never underestimate the amount of labor someone is willing to undergo in order not to learn something. Educators everywhere share your struggle!
Stale docs are worse than no docs. IME (at non-FAANG, non-tech darling companies) docs *always* go stale pretty quickly. No one wants to take on the thankless, unbudgeted task of keeping the docs up-to-date, or browbeating all the other devs to update the docs when they make changes.
The only docs I push for are stuff like swagger where the documentation is also living code. Otherwise I say just put it in the readme, and every repo has a clear owner responsible for keeping that readme up-to-date as necessary.