I am no longer maintaining github-backup. I'll contine hosting its website and git repo for the time being, but it needs a new maintainer if it's going to survive.
I don't really think it needs to survive. If the farce of youtube-dl being removed from github, thus losing access to all its issues and pull requests, taught us anything, it's that having that happen does not make many people reconsider their dependence on github. (Not even youtube-dl it turns out, which is back on there.) Clearly people don't generally have any interest in backing that stuff up.
As far as the git repositories on Github, they are getting archived very effectively by softwareheritage.org which vaccumes up all git repositories from Github. Which points to a problem, because the same can't be said for git repositories not hosted on Github. There's a form to submit them but the submissions often get hung up needing manual review, and it doesn't seem to pull in new commits actively if at all, based on the few git repositories I've had archived there so far.
That seems like something it might be worth building some software to manage. But it's also just another case of Github's mass bending reality around it; the average Github user doesn't care about this and still gets archived; the average self-hosting git user may care about this slightly more, but most won't get archived, even if that software did get built.