Yes. I've quite literally run a self-hosted CI/CD solution, and yes, in terms of total availability, I believe we outperformed GHA when we did so.

We moved to GHA b/c nobody ever got fired ^W^W^W^W leadership thought eng running CI was not a good use of eng time. (Without much question into how much time was actually spent on it… which was pretty close to none. Self-hosted stuff has high initial cost for the setup … and then just kinda runs.)

Ironically, one of our self-hosted CI outages was caused by Azure — we have to get VMs from somewhere, and Azure … simply ran out. We had to swap to a different AZ to merely get compute.

The big upside to a self-hosted solution is that when stuff breaks, you can hold someone over the fire. (Above, that would be me, unfortunately.) With Github? Nobody really cares unless it is so big, and so severe, that they're more or less forced to, and even then, the response is usually lackluster.