Iteration is how software moves forward. If slack didn't "re-invent" IRC, it wouldn't exist. Also, not everyone is comfortable having data exist on a 3rd part

Iteration is how software moves forward. If slack didn't "re-invent" IRC, it wouldn't exist. Also, not everyone is comfortable having data exist on a 3rd party system, that they have no audit access to. This is the fundamental difference between "founders" and people who know how systems work.