Microsoft builds its ecosystem around vendor lock-in. You're using Entra? M365 integrates real nicely with that. Oh, you want to use something else? Well, good luck with that, our documentation is so piss poor even CoPilot won't be able to help you. And once you drink the M365 kool-aid, now you have Exchange, Outlook, Teams and Office. You also get afflicted with SharePoint as a bonus! Good luck justifying anything else to your management.

Honestly, I don't see how MS hasn't fall afoul of EU anti-trust laws, again. They have bound everything up so tightly that you're lucky installing Windows doesn't obligate you to a lifetime of M365 subscription costs.

Interoperability becomes an issue though. FLOSS and federated systems help there, but we all know the big providers aren't going to play ball. Unless we rebuild the whole stack from the ground up, proprietary systems are always going to try to funnel everyone into vendor lock-in and platform monopolies. This is the end result of choices that were made 30 years ago, based on assumptions that didn't hold up, but none of us now dealing with the consequences, had any say in making.

Yeah, but a physical backup service in critical areas like fax could remain too.

That's less funny than I hoped.