From what I see, XMPP is "message delivery" while matrix is " eventually consistent global db with pubsub semantics" The difference becomes relevant when you h

From what I see, XMPP is "message delivery" while matrix is " eventually consistent global db with pubsub semantics" The difference becomes relevant when you have multiple or offline devices. XMPP may not deliver messages to some of the devices (for example, if message carbons are not supported by client). Matrix will not drop messages -- it may take some time, but eventually all devices will see all the messages.