I would argue that part of "truly caring" about open-source is being where the contributors and community are. That's probably a large part of the move to GitHub, and neither of these other options would achieve that. As much as one can say "git is distributed, the server doesn't matter", the centre of the community very much does matter, and for better or worse that's currently Github.
We need to work on decentralisation of git forges, making it less relevant where a project is hosted by offering cross-instance collaboration and discoverability.
If you maintain a popular project, you'll quickly find that github prs are a massive source of spam and low quality prs with people that don't even bother to follow up.
Bad PRs all around, with just a constant stream of drive by "why no merge?!?!?!" comments.
