It's very funny to me that all of our municipal EU customers requires that we host in EU. But they all run Microsoft online email, Entra and so on themselves.
I haven't tried to leave Gmail, but I've run email servers for 15 years and have never had trouble sending email to Gmail (get plenty of spam from them though). I often read people saying Gmail rejects mail, but I suspect such people are running mail servers on cheap VPS providers, who have bad IP reputation.
IP reputation lists predate Gmail by many years (eg spamhaus). I know Gmail used to use them, and may still. It would obviously make sense to keep their own stats as well.
I've successfully exited Google Workspace for email, calendar and contacts about two years ago. Went with Fastmail. It's been rock solid.
Unfortunately, Drive and Voice are keeping me subscribed to their service despite me wanting VERY BADLY to exit it. Neither have good alternatives that check all the boxes.
Sure but let's start with not having all citizens' sensitive data that EU state orgs store in american cloud, and then we can talk about creating an EU based alternative to google/apple in mobile.
They literally reject your emails. There is also nothing you can do if ms/google black lists you.
The only real solution for EU is to ban the operations of Google and Microsoft. China style. So that their ecosystem can breath again.