ive said it a thousand times, and i can say it again:

you can outsource the work, but you cant outsource the risk.

if you put microsoft in charge of your entire business system structure - email, calendaring, chat, file storage etc etc

and microsoft cuts you off?

thats on you. you gave them that power.
and if that means a massive outage?
it means you never thought ms would ever go down, or rugpull you, and didnt plan for that.