fossil (https://fossil-scm.org/home/doc/trunk/www/index.wiki) is of course better, but if git must remain, I believe the base infrastructure should be the mailing list. Patches, branches and releases can live inside a mailing list, it is naturally built for discussion with rights, and is a natural queue for third-party tools. I wish we moved away from centralized forges and started to use augmented development clients with the mailing list as the sole communication vector.
!? Wikimedia and Notion, just off the top of my head. And Confluence was initially just textarea inputs, its early WYSIWYG was engagingly bad.
Notion is supposedly able to do it: https://www.notion.so/help/collaborate-within-a-workspace#re....
Wikimedia is apparently working on it: https://www.mediawiki.org/wiki/VisualEditor/Real-time_collab...
Of course, having one of these apps that is yet-another-github with a local-first approach might turn to be great DX!
That's another idea of mine that's been brooding for a long while.