> That's not what Google does

I mean, that is exactly what Google does. Google does allow the change you listed above, which is nice. But if you don't explicitly change your accounts, you keep getting the "pick an account" screen on every single login, just like the parent described, and just like Microsoft shows users too.

Google's UI for it looks like this : https://lh3.googleusercontent.com/-_g4V2wYd-SI/VrZF-5K2yCI/A...

Which is very similar to Microsoft's UI for it : https://docs.microsoft.com/en-us/azure/active-directory/medi...