I have an alternative view to offer here, because this to me sounds like you are leaving out a significant part of mobile messenger evolution. Back when Smartphones weren't a thing most phones had JavaME, and the most popular networks for chatting were MSN, ICQ, AOL and others. I'll focus on ICQ specifically here because it's what's been popular where I live. It had been a messenger for people with computers, but then suddenly everyone started using it with an unofficial JavaME client Jimm. Literally every person with a phone, even though it was a complicated thing to do - you had to register on the ICQ website using a computer, build or download a pre-built Jimm for your phone (you had to cater it to the hardware, because phones had been very different back then from model to model) and log into ICQ from your phone. Most cellphone stores offered "Jimm setup" as a service for people who couldn't do it themselves. The reason for such popularity? SMS limitations made it very expensive to have long chats on the go, and ICQ demanded so little traffic that you could use it for a fraction of SMS costs. And of course, as most multi-clients at the time, Jimm had full XMPP support, after all ICQ, AOL and MSN were little more than slightly customized XMPP at the time. So switching to any other XMPP server was pretty trivial. Anyway, this lasted for a long time, and then, sadly, a smartphone "revolution" happened. People started getting smartphones left and right, and unlike JavaME phones they were much, much worse for ICQ, XMPP or any other similar network. See, a JavaME phone was perfectly capable of maintaining connection to ICQ servers in the background, without draining your battery life too much. It was seamless, most phones at the time allowed for at least one app to run in the background at all times. But once Android and iOS came along - suddenly a phone had to either be sleeping all the time or had empty batteries in a few hours, and that was awful news for protocols that relied on continuous connection, like ICQ did. The only smartphone that played nice with these protocols that I know of is N900. Sadly this, and this thing only killed XMPP, ICQ and others for an average person. If it wasn't for these protocols not playing well with smartphones, I have 0 doubts XMPP would be king right now.