As I said, it is not impossible to move away from gh compared to many other cases in other industries, just that it is more difficult than necessary because vendor-lockin is allowed.

If vendor-lockin was illegal, companies had more incentives to use established or create new standards to facilitate simpler migration between software stacks, without changing the external interface.

For instance allowing your own DNS name to be used as the repo/project basepath instead of enforcing github.com, Allowing comments, reviews, issues and pull requests via email or other federated services, instead of enforcing github accounts to do so, providing documented, stable and full-featured APIs for every component of their software, so that it is easy to migrate and pick and choose different components of their while stack from possible different vendors, ...

There are so many ways that would improve the migration situation, while also providing more ways for other ideas to compete on a level playing field. If a bright engineer has an idea for improving one component from github, they should not be required to write a whole separate platform first.