I guess the only solution is to self-host. I've even been migrating my dedicated server to a homelab I'm slowly building. But that's a very time-consuming option, has a high chance of breakage, and not even available for 99.5% of people. And most people don't wants to spend hours and hours of private time to babysit own email server, which is understandable. Finally, it's not free.

I wonder what would have to happen for people to become more digitally sovereign, but I doubt it'll ever happen. If anything, we're going in the other direction.