What would be nice is an aggregator site one could submit to and everyone just host it on their own internet connection, and nobody be dependent on a source for hosting their projects. Maybe something like bluesky with the AT protocol but with git repositories.
Have a look to [Fossil](https://fossil-scm.org/) which is very easy to host and offer code repository, bug tracker, wiki, forum, etc. It is not Git however, but there is bridges and one can even mirror a Fossil repo to Github.
For just text there's Usenet, Freenet, Mastodon. Though these work for more than merely text.
I suppose something like this with git and source code exists on Tor.
During the Arab Spring and Hong Kong protests, Bluetooth was used to share messages whilst the internet was cut off.
There’s Tangled[0], but I don’t have personal experience with it.
[0]: https://tangled.org/