So everyone runs their own gitlab instance, and there's some sort of gitlab "tracker" that you can search through?
>without discoverability
What is this "discoverability" you speak of? If you want a library to do "foo", do you search up "foo" on github and look through the repositories? Is this better than searching up "foo" on google?
>& interoperability
The only "interoperability" I can think of is for pull requests, and I do agree that having to make an account on the instance and push to it to make a PR is a pain. This can easily be solved by allowing remote git repos to be used as PR sources, and using social sign in for account creation (so you don't need to create an account to create contribute).
https://git-ssb.celehner.com/%25n92DiQh7ietE%2BR%2BX%2FI403L...
Anyway, hosting is not allowed/feasible on 4G (maybe also won't be allowed on 5G?), which is what everyone has.
The software stack isn't the issue, and smartphones are powerful enough to host contents, the problem comes from the current mobile telcos operators who doesn't allow hosting on their networks because of NAT/bandwidth/political concerns
[1] https://git-scm.com/book/en/v2/Distributed-Git-Distributed-W...
[2] https://gitlab.com/gitlab-org