so long as we're dogpiling Slack, let me add in my complaint: You can't mute Slackbot, and Slackbot sends a LOT of dumb and pointless messages about channel management. At work they're constantly adding thousands of people to "watch party" or other random channels, then archiving those channels later on, and I keep getting notifications from Slackbot about them.
I was trying to keep Slack notifications unmuted in case my manager needs something from me, but I was just getting too much useless crap from Slackbot. Finally I had to mute it completely and tell him to call my cell if anything comes up