alt Hacker NewsYes, 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.
It is the protocol's fault, and there is a solution at the protocol level: https://ircv3.net/specs/extensions/chathistory . So now, you can get messages while offline when using a modern server (eg. https://ergo.chat/) with a modern client (eg. https://codeberg.org/emersion/goguma)