I singlehandedly moved my entire extended family into the iOS space because I got tired of dealing with Google's bullshit messaging apps. I'm not going to waste my life teaching non computer literate people how Hangouts/Meets/Talk/Duo/Allo work.
WhatsApp came along and took the messaging space, while Skype and Hangouts and Talk or whatever couldn't figure it out. And Facetime was the only decent video calling option that didn't need to be troubleshooted.
It was ridiculous that I couldn't easily send a contact to anyone in the world until WhatsApp came around. Then I didn't have to worry about who had what phone, I sent them a contact in WhatsApp, they got it for free and it worked.
Look at the messaging space now. Messenger, WhatsApp, iMessage. Google should have led this space with evolution of Gtalk.
Even for users, as it used XMPP we would have had an open platform where we could have just plugged in our own favorite messaging apps with it.
That's my point though - the features that HN users find valuable (XMPP standard) are not the same as what most consumers do.
XMPP I consider as an advantage personally as with lock in to platforms like Messenger/WhatsApp we complain about the total control these companies have. In an XMPP world, at least you could have had more control over clients and the ability to talk to a different Jabber server from the same client app.
I agree though that the XMPP bit, no normal user cares about.