I cannot agree. Just try Conversations on Android and Gajim on desktop. xmpp is a solid and reliable protocol.
1. XMPP is solid. But without XEP is very limited. Client based on pure XMPP is almost unusable for people. 2. Tried to get list of supported XEPs for gajim. https://gajim.org/support/extensions is dead link - bad way to persuade me. After spending some time of googling, I have got list of supported XEPs. Will give it a chance again.