@daniel As a concept a messaging system built around a database could be valuable for niche uses, but most ‘real’ IM conversations I encounter are (unfortunately) on WhatsApp, and feature potholes, lost pets, family concerns and fun, and so on, None of these need to be protected against an adversary who might want to re-write their history, and were it not for the ‘But everyone uses WhatsApp’ would work as well on XMPP. There may be (I have not looked into it) similar concerns related to traffic analysis in Matrix as there are in WhatsApp