Not just GitHub
I know it appears at times that we like to make out that only Microsoft (sorry, Micro$oft) have any issues, and that if we all used anything else, the world would be a better place (and a chunk of the time that's not the worst of ideas), but we have the joy of using GitLab at work and that's almost as bad. It had one of it's regular afternoon siestas yesterday.
Most of us have no experience (but we have plenty of opinions. We wouldn't be commenter's if we didn't :-) ) of running stuff at the scale of some of these companies, and it has to be hard. Some of their own decisions definitely don't help though