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.
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.
For private repos and work stuff, we are working on actuated, which comes with unmetered billing minutes because you BOY machines or cloud instances.
ARM builds show to be ~ 20-30x faster than using QEMU too.
It was up on Hacker News recently, so you may have already seen it.