There's now quite a few GitHostingSites
Microsoft owned GitHub now taking down software that can be used for piracy.
Quora Answer : Is GitHub too big to fail?
I mean, it's unlikely to go bust because it's now part of Microsoft and will continue until either Microsoft go bust or they shut it down.
But that's unlikely to happen in the immediate future. More likely M$ will continue to derive a lot of value from it
1) By using the huge database of code it contains to train / test AI tools : from simpler source-analysis and refactoring tools, to automatic bug-hunting and fixing, to full AI coding.
2) It will be built out into a full cloud based development / CI/CD / hosting environment and service. I don't know if there's yet a 1-click "deploy to Azure" button appearing on some GitHub repos. But I'm betting that there will eventually be. Might GitHub eventually be rebranded as "AzureHub"? Maybe.
But if GitHub were to fail, would it be so big we'd feel obliged to protect it? Not really. GitHub is not Git. And much of the basic value of GitHub is really Git.
There's already 1-click migration from GitHub to GitLab or Gitea. Or I can grab a repo by typing git clone http:github.com/myname/projectname at my command line. The distributed nature of git means that none of that basic git value is locked-in to GitHub.