XMPP was supposed to solve all those problems when it came out in the early 2000s. But then all the big tech companies who build "ecosystems" decided to push their own applications, all incompatible with one another. So here we are again with this proliferation of programs that really only do one thing: communication. It's like the 90s / early 2000s with the proliferation of instant messengers: ICQ, AIM, Yahoo, MSN, and on and on and on. The players are different, but the game is still the same. I suspect that twenty years from now, when the players have all changed yet again, there will still be one reliable method of reaching me: IRC.
If the Googles and Whatsapps and Facebooks of the world had been around in the early 90s, you'd have one email client from Facebook for mailing Joe and Fred, an email client from Google for mailing Mary and Jane, and an email client from Whatsapp for mailing Alice and Bob. Thankfully, email became entrenched before that could happen.
I want messaging to be like email, where I use one and exactly one program to communicate with all of my contacts, regardless of what server they use. People say that federation is more complicated than centralization. I'm sure that's true for developers, but in fact, federation can be vastly simplifying for an end user. I'm a fundamentally lazy person. Having to learn all these different messaging tools is frankly a waste of my time. All I want is a federated protocol and an open system, be it Matrix, XMPP, or something else.
As a final aside, you know what else that bugs me? The word "ecosystem". I worked for a big tech company for a while, and the only people I ever heard use that word were people out to build a walled garden.