> Although, we basically have the same thing when people share links and people comment on them.
True, but having the comments appear naturally in context makes all the difference. Imagine seeing comments/corrections on a New York Times article that aren't moderated by the paper, or comments on a real estate listing that list all the problems that the listing omits, or reviews of a show on Netflix, etc.
Both! I see a lot of real estate listings where I'm sure the average browser is unaware that a large construction project is about to begin on an adjacent property and ruin their views. For rental listings, prospective tenants might not know about excessive noise from a nearby road.
True, but having the comments appear naturally in context makes all the difference. Imagine seeing comments/corrections on a New York Times article that aren't moderated by the paper, or comments on a real estate listing that list all the problems that the listing omits, or reviews of a show on Netflix, etc.