Yes, there is room for another Slack
Look at Slack condescending to Microsoft like “hey, we heard you were making a chat app, but we’re the best so don’t even bother!
Well I’m here to say that yes, there is definitely room for another chat app. Slack’s great, sure, but have you ever noticed how much memory it uses? It’s a little absurd. That’s because the Slack app is just an app wrapper around a web view — yes, it’s a web page.
Actually several web pages. One for each channel. And each one of those is meant to provide enough horsepower for running javascript, processing CSS, and all the other stuff web pages can do, which is way more than you need for chat. Below you can see the Slack Helper tasks in my Activity Monitor, one for each channel I’m active in:

Wow, 622 MB of compressed memory for chat? By comparison, Messages, a native mac app that does the same thing uses quite a bit less — 59MB.

The fact that Slack hasn’t invested in building a native app is disappointing, and confusing. The’ve got plenty of cash. So what gives? Slack will respond to my tweets (yippee) but my computer is struggling and the fans are blasting because of chat?
I was sad to see my dev team change from HipChat to Slack, and I welcome new alternatives. Slack has very kindly laid out the important points of group communication for all comers.