I would like to point out that xmpp still exists. Google Talk does not. WhatsApp killed xmpp, not Google
XMPP still exists - and I use it for chatting with one person. Nobody I know uses it. Techies I know use IRC and, more recently, Matrix. Or discord, disappointingly enough.
And I mention techies because the rest of the world is just happy with WhatsApp/Messenger/Slack et al.
What I’m getting at is that XMPP feels pretty dead in my experience. But who knows, maybe it would be in this same position regardless of Google like you allude to.
Because every time this argument starts, someone mentions how they don’t want the fediverse to go down the xmpp path, and the argument has its origin in this article
https://ploum.net/2023-06-23-how-to-kill-decentralised-networks.html
