I think one point being overlooked is that often it's harder to have deeper/more critical conversation irl without preparation since you don't really have much time between thinking and speaking, so it's easier to just go with the flow. On the other hand, in online discussion, it's possible to take time to think before speaking.

So irl I will often realize hours after a conversation that I would have disagreed with something, at which point responding likely doesn't make sense, whereas responding a few hours later is pretty normal online.