I agree, the author complains about something they actually do not understand. I'm sure many people will agree with the author, I'm not sure I do. If Slack changes something or does something that I don't agree with, I will find another solution. If it changes in a way that affects the workplace, we will find another solution. This is why other similar systems exist like Mattermost.

EDIT> Thanks for the downvote! Always fun when disagreeing with the echo chamber causes a loss in Internet points.