If everyone had their own servers, either they're centrally enough managed that they aren't really independent servers or the management overhead and chaos from version drift etc. creates a mess that overall lowers the reliability of the entire system. Sure, you won't have concentrated outages like this but your instance's overall uptime is likely to be lower.

Google Workspace isn't going to be any different.

Whatever. People did this shit for years with little downtime. Even with Microsoft's own products.