I'm still in my early thirties but I think I was probably one of the last generations where GitHub was not in basic monopoly for anything-git. At university it was still a decision which to use and some were still using Dropbox :)
So I think it was less of an issue back then, because not EVERYTHING was on GitHub. Now it gets more difficult to get people to do a bit more effort to contribute, is my feeling.
@0leil I come from the time when version control was an esoteric topic at first, tarballs and patches ruled. Then I started using CVS and along came Sourceforge, which many projects used. That was what git and GitHub are now, more or less. So yes, better tools, but still the same (centralised) setup. Forgejo/Codeberg are working on integrating ActivityPub by using #ForgeFed [1] and I have high hopes that that will introduce truly better ways and real progress.
[1] https://forgefed.org