I admittedly don't know much about XMPP, but I've heard that it relies heavily on XML, which nowadays can be an offputting serialization format. Is there a XEP for using JSON(schema) (or even more dev-friendly formats like protobuf)?
XML has a few drawbacks (serialisation), but I’m not sure if it being offputting is one; you could always simply pass it through a library such as xmljson [0], if you prefer to work with what you’re familiar with.