I have lots of warm and fuzzy feelings toward Matrix, but my take is that
XMPP solved my basic problem over 15 years ago. The problem being:
I want to talk to Alice, Bob, Mary, Jane, Fred, and Joe without having
to install ICQ, AIM, and Yahoo Messenger. Or should I say Facebook, Whatsapp,
and Signal? I don't know what Matrix buys me over XMPP, but at this point,
I don't care. I'll gladly drink the Matrix kool-aid, as long as it solves my
problem and somehow ends up being the clear winner among federated protocols.
I don't think XMPP "lost" because it was bad technology. AFAIK the big
players are still using it in various places under the hood. It lost because
big players want to build "ecosystems".
XMPP lost because there was no big player behind it willing to push it as far as possible under its public name. Only a community of enthusiasts and a steering committee that only cares about what is going in the next spec.
Matrix at least has a company pushing for it, so there's a better chance it'll have more success than XMPP; unfortunately we'll have to wait a few more years to see the difference.
tbf there was a big player (Jabber Inc), and they sold out to Cisco. Hopefully the difference is already visible for Matrix, or if it isn’t it should be visible this year.
I don't think XMPP "lost" because it was bad technology. AFAIK the big players are still using it in various places under the hood. It lost because big players want to build "ecosystems".