@rozzin I can understand that. Though I still find many XMPP servers don't support XEP-0280 so the problem persists even for non-encrypted messages. Having a well-configured XMPP server has been an ongoing struggle since I started using jabber.
In terms of E2E encryption there's an attack vector I've observed where two devices are logged in & one is left physically behind. That device is then used to observe conversations that were thought to be private. Hard to get the UX right around these.