FWIW to me the biggest lock-in GitHub uses is not providing custom domain name / CNAME support for what is ostensibly otherwise a hosting platform. The result i

FWIW to me the biggest lock-in GitHub uses is not providing custom domain name / CNAME support for what is ostensibly otherwise a hosting platform. The result is that not only do github.com-infected repository URLs for your project end up in the .git/config of users who clone your repository, but they end up in .gitmodules for projects that use you as a submodule, various package manager configuration/lock files for projects that use you as a dependency, and in any number of automated build processes for distributions shipping your software to end users; even worse, because we are all developers and like looking at code a lot of times more than prose, github.com-infected repository URLs end up becoming the de facto home page even for projects that did go out of their way to buy a domain name and make a website. The reality is that, once your project has been on GitHub long enough, the "switching costs" are actually artificially high to move to any alternative--whether another hosting provider such as GitLab or attempting to self-host your own repository--as what you are effectively doing at that point is forking your own project more-so than merely changing out a backend provider, with the result that these alternatives can't just be a better tradeoff or even merely have slightly better functionality: they frankly have to be MUCH better to get over the barrier to entry that managing to entice such a large number of open source projects to re-federate under a domain name that Microsoft was able to just waltz in an buy presents to a project hoping to make any kind of change... it isn't as easy as "the alternatives aren't as good".