I actively avoided IRC for years. I still avoid it whenever possible. And I've been developing and sysadmining for the web for more than 10 years now.
Frankly, it boils down to that I just don't like it. I'm more interested in getting better at programming, or learning about containers, or some other useful thing, than trying to figure out IRC's odd interface. Chat isn't something I should have to think about. It should just work.
So, I agree with most of what @vonklaus said, and disagree with the links pro-irc stance.
I've never used Slack, so I have no opinion on it.
You can master IRC with a few basic commands. In fact I rarely have to use anything more than /join, /leave and /msg <someone>. /me <some text> for announcing an action. That's about it.
(It probably helps that a lot of in-game chat interfaces use a lot of these same commands, as I'm a gamer as well as a programmer.)
There's a pretty nice web interface to IRC called irccloud.com which also persists your connection (so you can simply log onto irccloud.com somewhere else, and entire history is preserved).
Frankly, it boils down to that I just don't like it. I'm more interested in getting better at programming, or learning about containers, or some other useful thing, than trying to figure out IRC's odd interface. Chat isn't something I should have to think about. It should just work.
So, I agree with most of what @vonklaus said, and disagree with the links pro-irc stance.
I've never used Slack, so I have no opinion on it.