This is not only email, but also cryptpad cloud (replace google docs) and XMPP.
Self-hosting XMPP or SimpleX is far more private and secure than relying on a random third party server.

While I agree email isn't that private to begin with, this protects you against passive AI surveillance to a far greater degree.  And email has a big risk of aggregating all information about you.

The real benefit of our product is getting all of these services on a single tiny VPS, so you get the most bang for your buck