Personally, we use GitLab for all the internal repos at our company. We originally migrated because GitLab CI was free and GitHub didn't even have a CI solution

Personally, we use GitLab for all the internal repos at our company. We originally migrated because GitLab CI was free and GitHub didn't even have a CI solution at the time. We still use GitHub for our public repos since that's "where the community is." GitHub actions is great, although IMO a bit too prescriptive (I'd rather write a script that can run anywhere rather than spend time building up the mental model of the abstractions that are unique to GHA). But nothing beats GitLab CI + container registry; we put a lot of work into our CI pipeline and now we've got incremental builds with a Docker image for every service tagged per commit. And since GitLab Container Registry supports manifest v2, we can take advantage of BuildKit layer caching (I think GitHub registry supports this now too, but haven't played with it). That said, GitLab has its fair share of problems too. GitHub UI is way better, community/discussion features are better, and forking/public collaboration workflow is better. I'm glad there are two big players in the space, though; GitLab really lit a fire under GitHub to finally get them to start pushing new features.