Earlier quoted context omitted.
Obviously you can create IRC integrations for anything. But how many are installable with one click, like Slack integrations are? Having to write custom implementations is yet another extra task and point of failure compared to just paying someone to manage it all for you.
another "but". First "but it doesn't scale". Now "but integrations". There will always be another "but", and there will always be a link on the internet showing that it's been done already. "but shiny web gui" - https://thelounge.chat/ "but mobile app" - https://github.com/MCMrARM/revolution-irc "but it's complicated" - https://www.mirc.com/ since 1995 IRC does have limits. Some. One is that to make it "modern" it ne…
That's my entire point. It's death by a thousand cuts. Now I'm responsible for an IRC server, a web frontend, a mobile app and a bouncer.
The OP said "just run an IRC server". There is no "Slack or just an IRC server". There's "Slack or a number of connected, interdependent services you need to maintain". I'm not saying it can't be done, or that it isn't the right answer for some people, but it's also a lot more work (and thus, expense) than just paying for Slack. It absolutely makes sense that people do it.