I have no illusions that if Facebook and Google had started with proprietary and non-interoperable chat systems that XMPP would be flourishing today. I think that, by and large, we'd be in the same place with it.

People chatting from XMPP to Facebook to chat with folks probably by and large would've gotten Facebook accounts for the non-chat functionality that was never interoperable and not part of real time chat communication. Think groups and events.

If you only interacted with Facebook people over XMPP, you were locked out of a huge portion of functionality unless you signed up for Facebook even while XMPP worked.

A lot of people are focused on "extend" in the vein of Facebook and Google playing fast and loose with the XMPP spec and implementation until the whole ecosystem got fucked and then walking away. Which is a real danger. I mean, in a lot of ways Mastodon itself has already proven that. How much fedi drama over the years has been caused by Masoton unilaterally deciding something that other AP microblogging platforms just needed to deal with? Lots of people have beef with Eugen for a reason.

But even more insidious than that will be luring people onto Threads for ancillary benefits and then cutting off that large swath of the fediverse after the drain is complete. Then we would definitely not "end up exactly where we are now."

Imagine in 3 years. "Ohh threads supports a live chat thread feature but those threads don't federate. My friends are gonna do one while they all watch the season finale of Marvel Bullshit Infinity. Guess I could sign up for Threads to take part. Hmm I can still follow all my friends in the broader fediverse from here, I can just make this my primary account. Scratch that I'll make this my only account. Oh, what Threads is turning off federation? Oops sorry everyone else I have no way to reach you anymore, maybe you can switch to threads?"