See, my main issue is with Actions. If that breaks, there's little alternative for the more complex flows. Minor infrastructure changes could be done manually through AWS, but complex deployments would have to be replaced. That's a big task even with AI.

The pull request system and related machinery is useful, but Gitlab and the ilk can do the same. Even self-hosted solutions like Gitea. But I don't particularly have a problem with that living in Github. If there's an outage, break glass, force push to main.

The actual Git repository hosting part is trivial. If that breaks, Git is distributed anyways, push and pull to any random remote storage. All you need is SSH. The main headache is that automations would break as they are usually hard-coded to a given origin. That is solvable in a pinch, and we have setup mirrors in the past.

It really depends on your use-case and how much you are tied to them (Github authentication?)