This whole thread is various people saying "[This] is trash, [that] is awesome", with the next person claiming the opposite. I suspect most people with strong negative opinions here know enough to have felt the pain, and not enough to be able to properly reason about the system.

I've worked with Github Actions, Gitlab-CI and CircleCI in the last 10 years, and they've all been such an improvement over Jenkins, or god forbid, CVS with manual deployments, that I'm generally just counting my blessings.

For me the pain only came when not adhering to KISS. All the mentioned VCS are pretty much feature complete and only really differ on meta-topics (cost, license, lock-in) or niche topics (Actions marketplace, matrix builds, SSH on Runners). I've not yet run into an issue that would have actually blocked me, because there's always sh to fall back to in case of a bug or missing feature.