Link me a JavaScript library that works cross platform on both iOS and Android with unified interface in React Native. Ideally it's maintained and if you are asking me why I wrote it, it's also because there was nothing available 2 years ago.

Majority of JS XMPP libraries depend on the DOM for xml parsing - see strophe.js for example. This won't work in all JSC runtimes.

> The point is XMPP is a solved problem

Ye, which problem exactly? All of them are solved partially. Let me give you example, imagine you have a platform where users can chat in chatrooms (as simple as it gets really). On your platform you have a username and you are supposed to communicate with others with your username. You'd think xmpp is perfect! Nope, you'll have to fork the xmpp server for this use case. Why? Well, because XMPP standard supports nickname changing, which means in a context of a platform it would allow nickname spoofing. So you need to modify and add some security rules on top of it. "Solved problem" of course...