...Maybe that's the answer, we need a "hub" for the smaller missing things to start, you pop in your git repository when you join, and it can sit as a thin layer over your repo with issues, releases, etc... Sounds like a lot of work, but doing it piecemeal would do it.
I think trying to re-host git itself might be more trouble than its worth. My kingdom for someone to build this so I don't have to use ADO boards anymore.