SM platforms like Twitter and Facebook are Time Squares. People ignore most of the posts, stare at something for 2 seconds if it catches their attention in some way (bait usually), and point to what really interests them (retweet,…). And sometimes you stumble on an active discussion (in the analogy, it would be like pointing a camera to those involved and showing them on the big screen with speakers blaring)

Then you have forums which are like lecture halls, IRC like apps (Discord, Slack) which feels more like classroom (without the teacher) and finally, the direct conversations in Whatsapp, Messenger and Telegram.