Well that's quite easy, since hosting a server is a resource hog, most people are still on matrix.org, which gives it a special status in the ecosystem (even more special than jabber.org has been in the early 2000s fox XMPP). This allows them to "move fast and break stuff" on short notice (a few months), to bring the protocol forward and force people to upgrade. In the federated XMPP ecosystem, they essentially have to come to a community consensus between developers, servers operators and all other relevant actors to write a manifesto or a new spec that says "stop using $thing at $date".
In my opinion matrix, while being open-source, federated and easy to write clients for, is still a half-locked platform because essentially the matrix.org server is "too big to fail", and the matrix team is the only one who can e.g. offer consultancy over the protocol because nobody else can have a long-term view of its future evolutions (of course the matrix people are nice, and you can discuss with them, but that is still not a standards body).