I haven't checked back in a while but last I saw, Matrix looked a lot like glorified IRC with extra stuff tacked on.
And I would also require that people could join over links with similar capabilities like Discord (require Account Age, registered with Telephone numbers, automatic joining into specific room, room visibility and access based on roles, prevent embedding of media based on roles, proxying of any previews in the chat via the server... etc)
Because that is what some people want from a chat service. They want to be able to scrollback and see what happened overnight without operating some kind of server for that. They also don't want to necessarily have to login or have to worry about private keys.