I keep hearing about how it resulted in cascading failure and, really, the loss of email and calendaring shut down most companies - doesn’t matter if it’s self hosted or Gmail or EOL, you’re having an IT sick day if email stops.

The fact that so many companies rely on Exchange Online is the problem. Email is designed to be distributed and moderately resilient - it’s why spam is such a problem still. It’s not that all the eggs are in one basket, it’s that all the companies are sharing two eggs.

Also, stuffing all the copilot data into hidden exchange folders was a choice. I’m not convinced it’s a wrong one, it’s just an interesting one that has created a dependency. I don’t understand yet the reliance of Intune and Defender on Exchange yet.