[vlunkr]

With regards to forum conversations specifically, one con is that you have no idea what type of people are talking to.

In real life you make all kinds of judgement calls before engaging in a conversation. For example: Do they actually have an informed opinion on the subject? Do you value their opinion on the subject? Can they remain level-headed in a conversation about sensitive topics?

Additionally during the conversation, you're analyzing their responses. For example you may know them to be very sarcastic or pessimistic, and parse their responses accordingly.

In an online context, everyone is going in blind, so conversations are not usually productive. You might have a well thought-out comment, but it will be rejected because you didn't know you were dealing with teenage edgelords, old racists, bots, or whatever.