Apple Services Outages Question

Sort of a first in my experience.
As of 5:21 p.m. PT there are a number of flagship outages

I say flagship … as a way to refer to such services as Apple TV, Music, Subscriptions etc
My main curiosity is what causes these, somewhat rare I hope, occurrences?
Does this relate to actual hardware power anomalies … in the manner of, oops, shouldn’t have
switched off that breaker on the Main Panel? …

even though when I clicked through the link to System Status one of the things listed as down was “Apple Music”, I haven’t noticed any interruptions today, and music is playing right now. Maybe it is a regional outage?

Apple Music - Outage

Today, 5:57 PM - ongoing

Some users are affected

We are performing routine maintenance, with no expected user impact.

While all resolved now, for me the (noted) outages involved
App Store
Apple Business
Apple Music
Apple Music Subscription
Apple School Manager
Apple TV
&
Podcasts

The note on the outage page, at least fir AppleTv, said it was down for routine maintenance.