I never worked on any SaaS that had such high uptime. It seems pretty good to me. In 10 years, it was always better than 99.5% uptime. That seems impressive to me for a huge, complex SaaS like GitHub.
This graph is literally designed to abuse correlation =/= causation by attaching the arbitrary label "microsoft acquires github" so that the reader will apply causation to the uptime.
Now let's overlay ontop of the uptime graph a few lines of: # of monthly active users, # of monthly commits, size of PRs, action minutes per PR (whatever demonstrates scaling)
Something tells me that the uptime issues follow scale more than they do ownership... but that's not the narrative that this chart was designed for...
Uptime: 4 9s minimum for paying customers for the core service (not necessarily the social features, but pull requests have to work).