5. Is it “sticky”?; does it have a moat?
No, Slack does not. There is a preference factor vs a corporate relationship factor in Slack vs. Microsoft Teams. They both perform the same functions in somewhat different ways. Some people detest Teams and prefer Slack, and some people are fine with Teams (in my recent experience, Slack can get “love” and Teams can get “yeah, ok”).
Companies that are going with MS as a platform provider (Azure, O365, SPO) are getting Teams as part of the enterprise package (replacing Skype formerly Lync). Non-MS companies are going Slack. But, they both perform the same collaboration functions; it’s that Slack does it in a more lightweight and less tightly coupled way, and Teams… is tied to O365 and SharePoint. (cough).
FC