Has anyone tried one of the third-party mail apps?
My Google account is my backup (I mostly use hotmail, have had it for over 17yrs now;-0), so I rarely actually sign in, keep it running as secondary in Outlook (desktop app) to prevent it from getting terminated, for occasional use.
If one of the third-party apps work (they get pretty good ratings actually), it would be something to "bridge", and most likely (hopefully) they integrate contacts and calendar.
Not saying I've tried this, but I did try the Google setup and got the compatibility error everyone else is, I'm sure it's being looked at.
To be fair, Google hasn't been making it easy, they more or less killed the ability to use Google Voice on the Edge mobile browser, where it had been working previously. I think both companies are a bit "at odds" right now, but I'm positive MS will fix this, soon.
Years ago, things were similarly at odds with Netware/Novell, but compatibility issues were a priority 0 problem, almost without question, MS wants you to be able to have an integrated experience.
I wonder, if this might also be broken on the Win10 desktop app...