Gitlab CI has some tech debt from accumulating geological layers of different ways to do things, but overall it's pretty good, it scales to more complicated setups, and it's not too painful.

Now the best way to use GHA is to do the bare minimum. Put all your CI logic in a script that you can test locally, and just have GHA run your script. Even that is painful. And, somehow, impossible to make secure without having spent 5,000 hours reading all the previous ways people got pwn'd by Github Action's horrendous security model.

My main problem with Gitlab is that after years I still can't find what I'm looking for in the UI. It's always exactly in the third place I look. Otherwise Gitlab has been good. Even self-hosted works pretty well.