I understand why Slack would want to stay away from an open protocol, since their business is so tied to building a moat around keeping businesses on Slack. Eve

I understand why Slack would want to stay away from an open protocol, since their business is so tied to building a moat around keeping businesses on Slack. Everything they do is to make Slack better and stickier for businesses. A counterpoint, though, is to think about the long game. Since email is an open protocol, it will likely _never_ go away. There is incredible leverage around this. Businesses & tools built on email will work for a long, long time. There is a legitimate business case to be made, today, for building things on email, and that, in turn, makes email stickier. Perhaps Slack stays forever, but perhaps not. It's possible that a new productivity fad comes into play and makes chat apps a thing of the past. If it's built on an open protocol - and an open protocol that's not restricted to one workspace - then Slack will likely exist for a long, long time.