Slack has been positioning themselves to be an integral tool used in the workplace. They dominate communication, but now are getting rid of one of the most important features for developer communication... You serious? What good is screen sharing (while pair programming) if you can't share control of your screen?

You're telling me that I have to download another application, and convince me teammates to do so as well? "Oh I immediately see the problem with this code you're showing me, but I can't do anything about it. Let's hop off this call and start another call in a different application!"