having a tool intended for a purpose doesn't necessarily mean it fits that description without issues. the xmpp world is filled with a heterogenous plethora of clients of various quality and encryption duct-taped on top of about a third (made up/guesstimated number based on nothing but my gut feeling having gone down that rabbit hole partly). even if i convinced all of my friends to switch, there wpuld be no client for all platforms and learning miltiple programs to use a single protocol is bad UX imho