IMO Git is already quite resilient to this kind of breakdown. Even if your host shuts down, everyone who has a clone has the development history and can become

IMO Git is already quite resilient to this kind of breakdown. Even if your host shuts down, everyone who has a clone has the development history and can become the host, continue with another host, accept patches over email...or patches on paper napkins. The main problem with services like GitLab is that they are not only hosts to repositories. They're issue trackers, they're CI/CD platforms, they're release artifact hosts, they're discussion platforms, they're review platforms, they're their own bespoke pull/merge request workflow; all eggs in one basket "as a service". If they shut down your repo, the code is the last thing to worry about unless they have the only copy of the current canonical history.