Gitea and Forgejo support OAuth integration and AGit Flow*, which is a breath of fresh air compared to the connected "fork" and PR strategies. It's a good middle ground between the "modern" method and email collaboration. With some UX tweaks it could become very accessible for many.

Available platforms like Codeberg provide the option to sign in/register with GitHub and GitLab auth, so needing "yet another account" has become a much weaker argument.

* https://forgejo.org/docs/latest/user/agit-support/