When one firm is so dominant for so long, the question is more like “Why shouldn’t we just use GitHub like 80% of software companies do?”

The issues they’ve had are almost all very recent. Very few companies have reevaluated that decision, because moving a big and well-integrated part of infrastructure is a huge project that delivers no value to the business. Speculating that you’ll have fewer development-slowing outages is not the most convincing when asking for the budget to do this. Plus, self-hosted isn’t necessarily going to have better uptime - mistakes happen.

I think before Actions, it would have been a lot easier to migrate off GH though. You’d just need to change a lot of repo URLs and find a way to set up webhooks from the new place to poke CI. Now with Actions, a lot lives in GH and in a proprietary flavor that doesn’t just ‘lift and shift.’