Decentralisation worked fine back when every project self-hosted their VCS/webpage/mailing list/bugtracker/build servers...
I wouldn't call that "fine". It was just like that back in the days but platforms like GitHub really gave open source projects and the complete community a major lift imho by providing visibility, simplicity and a lot of features that made organizing the projects a lot better.
And do we really want to go back to Bugzilla and mailing lists? Brrrr! 😉
There are other bugtrackers than bugzilla, and there are three providers of GitHub-like tooling that you can self-host anywhere (GitLab, Gogs, Gitea). No need to involve yourself with mailing lists if it's such a bother.
We've put too many eggs in the GitHub basket and we're paying the price now.
Imagine what happens when Rust crates are orphaned because of something like this, since they tied their infrastructure to GitHub.
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.