> If your stance is that IRC is irrelevant to this thread because Slack and IRC solve different problems
I was saying you are comparing Slack to IRC-when-used-to-solve-a-different problem. You haven't described IRC as it could be configured to handle the same problems as Slack, only when you've encountered it in the admittedly more common case that it's intended for drop by traffic.
IRC doesn't work "perfectly fine", at least in the context of the problems that Slack solves.
I think we largely agree on technical matters; it's a matter of what relevance this has to the OP -- a Slack client for the terminal.
If your stance is that IRC is irrelevant to this thread because Slack and IRC solve different problems, then I might mostly agree. But I didn't bring up IRC!