Yes, but compared to "modern" apps IRC is very rudimentary and you would not get messages if you "close the app". You always have to run some secondary infrastructure like a bouncer to get offline messages or see what happened while you were away.

I know that's not the fault of the protocol itself, but that's always one of the biggest hurdle for IRC adoption when everyone is used to just open apps and see the full history at all times.

The protocol needs ugly extensions to have a variety of devices plug into the same user account. For me back in the day this was an ssh session running the IRC client in a screen, and it was no worse than whatever else was available.

Mobile devices are different devices with different constraints. The main blockers are intermittent connectivity and the need to save battery life.