I agree with all the points made about GH actions.

I haven't used as many CI systems as the author, but I've used, GH actions, Gitlab CI, CodeBuild, and spent a lot of time with Jenkins.

I've only touched Buildkite briefly 6 years ago, at the time it seemed a little underwhelming.

The CI system I enjoyed the most was TeamCity, sadly I've only used it at one job for about a year, but it felt like something built by a competent team.

I'm curious what people who have used it over a longer time period think of it.

I feel like it should be more popular.