Probably because the system is new and they are still working through the bugs. When, for example, is the last time you noticed a Gmail outage? Nowadays almost

Probably because the system is new and they are still working through the bugs. When, for example, is the last time you noticed a Gmail outage? Nowadays almost never, but 10 year ago it happened multiple times a year. Similarly, GitHub outages are also becoming less long and less frequent.