XMPP is decentralized in practice (as opposed to Matrix, which is decentralized in theory, with everyone using the same client on the same server using the sole

XMPP is decentralized in practice (as opposed to Matrix, which is decentralized in theory, with everyone using the same client on the same server using the sole available server implementation). There are hundreds of public servers and dozens of clients. Nobody runs marketing campaigns. Judging by the state of most transports, actual long-term interest in that feature is limited. I don’t know if Matrix does something in a sufficiently different way for bridges (apart from ICQ) to be actively used. Commercial services, by necessity, try to differentiate themselves. That prevents full interoperability.