IRC’s not as popular as in its heyday, and while once it was the main choice for multi-playing gaming chat (Quakenet et al), that’s largely gone elsewhere, but it’s still very good for certain technical channels.
IRC has also proved to be remarkably resistent to commercialisation, mostly due to the users. Even when one of the biggest networks, Freenode, got taken over by a drug addled mentalist Reference who started insisting all all kinds of strange things, the users just upped sticks and created a new network. A bit of fuss, but the important stuff stayed the same and it’s continued much as before as a new network, Librenet.