Interesting. It seems that perhaps a good mental model for solutions like this is to start federating to each other rather than to centralize and create replacement walled gardens. Mastodon style activity feeds might be a good starting point for this.

The value of Github is not just hosting projects and issue tracking but the notion that it's probably the largest professional network of developers that can interact with each other, create pull requests and issues on each other's projects, etc. There are many GH alternatives but very few with the same global network of essentially almost every developer out there.

Instead of everybody creating new accounts on each other's not quite Github clones with only a handful of users, why not improve on the state of the art here and allow people to use their user account from a server of their choice and create a proper alternative to Github?