Depends on what you’re into. It’s kinda like discord, in that it has a lot of servers for specific communities/apps/games, etc.

I used it mostly for pirating cause it was always blazing fast compared to torrenting.

Libera.chat, IRCNet, Undernet, Rizon, EFNet are the biggest networks I can think of off my head. Each has like 5000 to 20000 channels!