Self hosted email, chat, messaging, calls is the future. Individuals will own host and run their own services for these on public clouds. There is no reason for giant corporations to own these services.
I admire your enthusiasm, but most users don’t want to think about or manage these things. Convenience and consistency of experience is the reason for giant corporations to own these services, and unless there is a compelling shift in consumer preferences, that seems unlikely to change.
A million upvotes. $50/year for FastMail to host my email is worth more to me than spending even one hour a year debugging mail server issues on my own hosted instance. Not even once!