It doesn't really seem to have a dependence on github, so much as a dependence on git. You can push to a git repo anywhere, even publish a site with it. For example the method I've used is no longer documented on the open web but an archive is here: https://web.archive.org/web/20220817005415/https://neurobin....

Also I think you're confusing "free as in beer" and "free as in free" here. The last thing any alternative social network needs is to bake capitalist incentives into the model, as that would just lead to everything optimizing for the same dark patterns and influencer garbage people want to avoid. There already exist plenty of ways to help people economically.