That's... not how it works for any human being. The whole point of a conversation is that you can engage in it while it's happening. You make a point in the middle when it's relevant, and someone replies with something else they feel is relevant. When you've already had a 30+-minute conversation over lunch, no human is going to remember it and copy to Slack, no remote worker is going to go through and respond point-by-point as if they'd been there in person, and no human who has already invested that time and energy in the conversation is going to re-start the conversation at every juncture just to explore alternative directions it could've gone in person.

What actually happens in the best case is you give a few sentences of summary if you believe it might impact your coworkers' work, and then schedule a meeting if there's more to discuss. Which (ignoring the fact that even the best people don't always do this) is great, except you could be entirely wrong about whether there was anything beneficial for any coworker to hear. That junior engineer on the team might've been able to overhear how you fixed a problem that was second-nature to you, but now they don't. That dude who just returned to work might've been able to tell you they were interested in picking up the work you were overloaded with, but now they don't. That team lead on the adjacent team you would've grabbed during lunch with might've told you they were planning to handle the larger problem next quarter, but now they don't. etc...