> I work for Slack

And? Your opinions are either insightful or they aren't. Who you work for is irrelevant.

This also isn't the brag that you seem to think it is. Your client can't even keep straight "what was the last thing I read in this channel." I'm constantly having to scroll back down because slack thinks I last was in the channel a day or two ago, not 5 minutes ago. It's also hopelessly bloated, uses GPU time when nothing on the screen is changing, slow, thinks everything is a URL, and the link previewer seems perpetually down.