I don't even agree that Google killed it, because it's simply a messaging protocol, it doesn't "die". Maybe you could try to argue that Google killed Jabber, but I used Jabber back in the early 00s, pretty much nobody else did lol, almost all IM communication was done over MSN Messenger. Google Talk brought XMPP "users" and they left when Google sunsetted Talk in favour of Hangouts. Facebook Messenger used XMPP for a time, so if anything they "revived" it (they didn't, it was never dead), but, like all the other messaging apps, they moved to their own proprietary version to add their own features.

This is what XMPP was actually designed for, the X literally means "eXtensible", whether it's extended open source or into proprietary versions.

I feel like there's a lot of anti-tech misinformation on Lemmy and it's great to be skeptical, but honestly I think we waste a ton of time being easily ragebait'd into the wrong shit.