IRC is great in many ways: not centrally controlled, open specified, not proprietary, easy-ish to implement, and quite common in my circles.
It's also archaic, unpleasant to use, and a bit of a mess. But it's still the real time chat system I use the most, because that's where most of my friends are.
@liw I miss when I had an IRC channel with a bunch of my RL friends, pre-Facebook.
@liw As you probably know, matrix.org is the modern replacement. Most of the upsides and few of the downsides of IRC
Lars and friends