IRC was designed, mostly, for two types of users: A) Large institution users who had a fixed link to the internet and ran in their shell on a mainframe. B) Dial-in users, who's devices mostly stayed connected, and when they disconnected, usually required manual intervention to get back on.
Anyone, and I mean ANYONE using a mobile phone SHOULD be using a 'bouncer' or other gateway to access a live communications environment. This would be more like use case A where someone has a small agent on a slice of a server they 'trust' and that maintains state (for their client) and stateful connection (for links to other servers and users).
IIRC, Quassel IRC has such a client/server model for the client, there are probably others too.