> I have... never met anyone in real life who doesn't like slack. I only hear negative opinions about it here.
While I have literal never discussed Slack with someone who likes it. Actually not completely true: at my last company one developer thought it was great but after a few months I heard her curse it as a "place information goes to die". In my experience it doesn't scale beyond a very small number of people who know each other well. Sending commands from its command line is not as easy as simply sending them from, you know, the command line (which is scriptable).
As a side point it astonishes me that after all the money they raised and people they hired they can't get video working on mobile, just laptop/desktop.