I think a happy medium like signal would be much better, slack is an immovable part of much of the (white-collar) business relationship world now but it'd be nice if there were assurances of secrecy and security in communication as 24/7 cyberattacks rather than a company whose security is based solely on promises rather than zero-knowledge systems. Signal has had far and away the best cross-platform messaging experience of any client I've used in friend groups but moving to a slack-like system alongside what exists now would be much appreciated to the noisy channel approach.