I just finished convincing old-school management to move to Office365/Azure/Teams after we've been doing everything on-premise, saying we can reduce our maintenance and increase in reliability since we're a small operation. Needless to say this isn't a good look for me.
Their reliability only looks bad in comparison with other cloud providers. Microsoft can still probably do a much better job compared to a small team.
This eliminates a lot of moving parts and things that can fail. Imagine an Nginx server running on a single machine. There's very little that can go wrong here beyond hardware failure (and certain types of failures can be mitigated with things like RAID), and yet it is probably enough to host most internal websites.
Now compare this to something like Azure App Service which is obviously more complex to be able to support many tenants, load-balance, etc. There is much more that can go wrong with the entire App Service infrastructure (due to its complexity and moving parts) than with a single machine running Nginx, and the complexity will also delay disaster recovery efforts (this outage is now lasting for more than an hour - you can reinstall an entire Linux web server from scratch in half that time).