XMPP servers are really good these days, you know. And, I repeat, if you run your own server, you
don't really need e2ee, cause the only one who can access the DB with your messages is a server operator - yourself, i this case, and why would you protect you from yourself?
Also, if you are concerned about privacy, chances are, you are not a private individual and have specially trained people to install that server for you.
Then again, even if you DO need encryption to transmit a critical password or something, well, XMPP clients developers know their business (at least, some of them do), so it is unlikely that you'd be able to screw up something.