irc died and was replaced with nothing
Individual channels are dead, sure. 15 years ago, EFnet's #wow was quite busy and frequently had over 100 people in it. Now, it's down to just 20, with at least 7 of them being bots, the rest are idle. We went two weeks without a single message. I even unbanned the trolls just to get some excitement back, but they went silent (though didn't leave) once they realized the channel is indeed dead.
But EFnet's #geekissues is still very active.
Also yungins might be surprised to learn that we had a distributed, open source communication network, where basically any dipshit with a static IP and a Pentium could start an IRC server and maybe get added to the network if they were reliable enough (I was one such dipshit).
So you are right in a sense that discord replace IRC as a means of communication for the majority, but in term of freedom it is a regression. If IRC had supported offline history keeping things could have been different, but for the people I know it was a major blocker for adoption. They didn't want to have to setup a server to bounce from or keep something running all the time.