The problem that I've found is that no other CI/CD provider has feature parity to GitHub Actions & integration with Git. Sure, there's external providers (Travis-CI, Buildkite, etc) but none of them feel like they have the polish of GitHub Actions. GitLab & Azure DevOps also don't compare at all - I've migrated whole organizations off of both because they just don't feel polished / break rather frequently. So I'm personally stuck with GitHub, simply because no other company provides anything better.
GitLab CI is definitely competitive with GitHub Actions. What's the specific feature set you're missing? "Polish" is pretty vague, especially in the context of a post that laments GitHub Actions' poor uptime record.
Not at all true. GH actions are about as simple as they can be and can be replaced by mostly any other commercial service that does the same. Also, any CI/CD tool can integrate with GH.
Gitlab IMHO is definitely in parity, if not better. I've had loads of success with it at a few places now, using basic stuff right up to full Autodevops with custom buildpacks for Elixir/Pheonix.
I have the exact opposite experience. GitHub CI is probably the worst CI I've used so far (except for custom homegrown messes), and Gitlab CI by far the best.
GitLab CI isn't even on the radar. I'd take Actions or Buildkite anyday over the existing offerings. I'd argue the GitLab CI ecosystem is non-existent.
When I talk to Hashicorp or AWS they provide tooling specifically for GitHub Actions. I don't see the same level of vendor commitment when it comes to GitLab. If I'm not going to get vendor commitment I might as well run buildkite which is awesome or even look to something like Tekton for Kubernetes if I'm just doing Kubernetes anyways.