It about incentives.
What Wikipedia illustrates is that the problems with Facebook, Twitter, YouTube, and other social media platforms aren’t that they are social or that they’re populated by user-generated content. It’s their business models. All three are for-profit companies that make their money through micro-targeted advertising, which means they have strong incentives to show users content that will keep them on their platform for as long as possible and keep them coming back. Content that confirms users’ beliefs or stokes their preexisting resentments can be good for business. That only overlaps with the truth some of the time.