Backing up another level...it’s concerning to me when a language relies heavily on single-maintainer libraries for commonly needed functionality.

If actix-web was this important, it should have been adopted by the community before now. Maybe languages need a way of setting the expectation to that if your library becomes essential to the community (and if licensing allows) the core developers are going to fork it and find a way to govern/maintain it the same way they maintain the rest of the project.

I think about this a lot with Racket lately. Some of the core packages that everyone uses for date/time, Markdown parsing, etc., were written by a single guy in his spare time, who a few months ago was making noises about quitting the language (so far so good though).