Comment by bsimpson

Slack had the ability to be Discord, but they explicitly decided they wanted to be business-only.

React was the first open-source community I knew of that outgrew/got kicked off of Slack and moved to Discord. Now, it seems Slack is only used by companies, and occasionally by smaller groups (apartment buildings, school parents, etc) where someone in the group knows Slack from work and doesn't know it's hostile to non-businesses.

Discord was the opposite. I was working on an open source initiative at Google at the time, and the Discord folks openly welcomed us. They even gave us someone's contact info, in case we had needs they weren't addressing. This was when it was still targeted just for gaming, but they were very welcoming of OSS projects using it too!

As I write this, I realize that Discord is what "Google Apps for your Domain" was and Slack is the "Google Workspace" it became.