client or server that doesn’t support the same encryption protocols
Outside of TLS which most any server uses by default, XMPP or not, the server is not responsible for E2EE. Conversations Compliance & Are We OMEMO Yet have existed for a long while & I never see anyone recommending a client not on these lists so while certain features may be fragmented, the communication essentials have been more or less established for years now. XMPP is an extensible format, and some applications that aren’t for chatting with your friends/family, don’t need many of these features which allows the protocol to morph into something stripped down for the task… which is why the base spec is basically barren, & community XEPs are what folks get behind for adding new features for different use cases.