Travis the company had an exit a few years ago, the general feeling since is that the product isn't really maintained anymore. If your needs are simple, GitHub Actions works well, if you need features like insane parallelization, use Circle.
Github Actions supports heavy parallelization and fan-in/fan-out jobs just like CircleCI does, so I'm curious if there's some limitations that I haven't ran into yet. I'd go farther to say that their documentation is much richer and easier to search for.
Last time I didn't use Woodpecker for my projects/projects I was involved in (so maybe one year ago last time?), GitHub Actions were a bit harder to debug as you don't get ssh access as you get with CircleCI. Being able to just ssh into the builder/worker when something goes wrong, cuts down debugging time so much.
There does appear to be some solutions on the marketplace that will allow you to ssh into a runner, but I haven't had a need for them as of yet.