IRC is still alive in the fact that people still use it, but its dying (less people use it over time) in a way that will never be overcome.
IRC is lacking so many critical features that people consider the fundamentals of IM now. IRCv3 has been in development for forever and they still aren't done and even if they finished it it would never make it to all the irc servers and clients.
At this point it makes sense to join most other open source projects in moving to Matrix which still has active development and the ability to actually push out new spec changes in the current decade.
I think IRC will always have a place in certain communities.
I drop into IRC whenever I need help with an Arduino project or want to catchup with old colleagues. From my own personal experience, all the open source communities I get involved with use IRC and I have never known one use Matrix, sometimes this is for personal reasons and sometimes for work. This probably depends on what techie circles you move in.
I've also noticed IRC is more popular in certain countries. Anecdotally Brazil and Sweden seem to have fairly large communities of nontechnical people on IRC.
Maybe for some people, IRC does what they want and they don't need any updated spec.
The mere fact that we always see several people jumping in to assert how IRC is alive and kicking is in fact a giveaway that it, if not actually dying, is at least starting to smell a bit funny. (And frankly I say - good riddance! It's a protocol that's at least a decade past it's sell-by date, modern options are so much better)
People often don't seem to use modern alternatives like matrix though. I often see people switching to whatever the popular walled garden of the year is instead. Personally I prefer an open ecosystem to animated GIFs, even if it might occasionally smell.
IRC is lacking so many critical features that people consider the fundamentals of IM now. IRCv3 has been in development for forever and they still aren't done and even if they finished it it would never make it to all the irc servers and clients.
At this point it makes sense to join most other open source projects in moving to Matrix which still has active development and the ability to actually push out new spec changes in the current decade.