Github Actions really is a freakin awesome product. Yeah, there's lock-in, but their free plan (and cheap Pro plan for individuals) offers a great value. And, really, CI is CI; if you ever need to migrate, even for this guy with hundreds of projects it should only take a couple days. Once you've seen one CI yaml file, you get the gist of what all of them do.

Other options:

* Gitlab CI. Good value, great integration with Gitlab, has integration with Github.

* CircleCI. Something of a gold standard in CIaaS among growing companies. But, it goes down a lot, and the new UI isn't an improvement. But, it works and its a good value. Word of advice, I'd avoid using their "Orbs" if I were you. You can accumulate a lot of lock-in with those, and they're infamous for stability issues. Instead, use their docker builder and just build a base docker image with all the stuff you need installed.

* Buildkite. Really cool product; they handle the control plane and the UI and webhooks, you host the runners. Its a simple binary or docker image you can install anywhere. If you're looking for something with low lock-in that's still easy to manage, Buildkite is a great option. I'll warn you though: if you're going to do any kind of cloud hosting for your runners, and you want to build docker images, best to avoid their dockerized runners. Just install natively on a linux box, either manually, with an AMI, etc. Docker-in-Docker sucks; not impossible to get working, but not worth your time.

* Jenkins/JenkinsX. If you want something with zero lockin but also hard to manage.

* AWS CodeBuild/CodePipeline/CodeDeploy. There is, like, no one I feel comfortable recommending these options to, but people still use them because they're AWS.