Oh man, all of those things are so convenient once you start using them. If you've never used them, great, irc is probably fine. For me, I could never ever go back to irc, having gotten accustomed to all that stuff on slack.

For example, want to share a screenshot? Hit print screen to capture it, click to the browser, click to the tab, hit ctrl-v to paste, done. Instead of, what, uploading an image to an image-sharing site? I wouldn't even know how to do that at this point.