The problem with chat-based solutions is people get lazy in articulation. So instead of a cohesive idea it’s spread across a giant thread. And instead of actually creating a proper document, it’s easy to say, “Meh, I’ll do it later it’s in slack.” But then it never gets done, and the info is privy to only those in the conversation.
It can be good or bad either way, but there’s no substitute for in-person communication; and there’s no substitute for a thoughtfully constructed document.