[InfiniteRand]

I think the decline of xmpp can be traced to the rise of text messaging and phone messaging in non-open protocols. One factor that made non-open protocols more palatable on the phone than on the desktop is the easier and relatively more secure nature of phone apps (I don't think phone apps are that secure, but I think they are more secure than installing random exe's on your computer). If you're willing to install all of the apps, yeah having everything in one place would be convenient, but there's only two or three apps you care about so it's not a huge thing. Moreover most of the phone apps liked to keep things closed. That's just my thinking.

[hot_gril]

It's also branding. Regular people don't understand clients being separate from protocols being separate from servers. Multiple users sorta need to be on the same XMPP server to talk to each other (yeah there's federated mode but it's a mess), and in modern times there's no way that server isn't run by a huge company that also distributes its own client. And there's no way, controlling both the client and the server, such company will stick to pure XMPP instead of adding tons of proprietary stuff on top to improve the experience and establish control. Hence WhatsApp, FB Messenger, etc were born?