Yeah, I got so frustrated with the odd workflow (having no sane way to locally test new/more advanced pipelines and having to do lot's of "change .gitlab-ci commits") at work that I started investigating alternatives.
At home, for some hobby projects, I've been using earthly. It's just amazing. I can fully run the jobs locally and they are _blazing_ fast due to the buildkit caching. The CI now only just executes the earthly stuff and is super trivial (very little vendor lock in, I personally use woodpecker-ci, but it would only take 5 minutes to convert to use GH actions).
I am not a fan of the syntax. But it's so familiar from Dockerfiles and so easy to get started I can't really complain about it. Easy to make changes, even after months not touching it. Unless I update dependencies or somehow invalidate most of the cache a normal pipeline takes <10s to run (compile, test, create and push image to a registry).
This workflow is such a game-changer. It also allows, fairly easy, to do very complicated flows [1].
I've tried to get started with dagger but I don't use the currently supported SDK's and the cue-lang setup was overwhelming. I think I like the idea of a more sane syntax from dagger, but Earthly's approachability [2] just rings true.
[1]: https://dagger.io/
[2]: https://earthly.dev/