Emacs provides a better UX, Visual Studio (proper) provides a better UX, Sublime provides something close, although not as good. Slack's UX is incredibly basic.

Emacs provides a better UX, Visual Studio (proper) provides a better UX, Sublime provides something close, although not as good. Slack's UX is incredibly basic. It's a couple of steps above a basic CRUD app. There are billions of IRC and XMPP clients ranging from toy to professional-quality, I use IRSSI, which is admittedly basic, but I find it hard to believe that there is no better native chat UX in existence than Slack's.