Have to weakly agree here. But a very important point is missing, github actions. It is a pristine example of vendor lock-in.

Also the interconnected pr references by #prnumber across many repos will make it very hard to keep track of future development in any foss github alternative the project moves to.

So until git-bug etc., mature enough to include everything in git itself, or people start using gerrit, email patches etc. which are all non-trivial compared to github prs, giving up github is harder than giving up google search.