If you have ever set up ads in an big system like Amazon or Google you can see exactly how it works - the more you pay the more your ad gets seen. The more you refine your demographic audience, the more specific content targets them.

Are the websites complict? No, because they get paid to unbiasedly post content that is paid for using their pay scale and the customer's algorithm. And their job is to rank and sell for who pays them and we have to realize that.

And yes, because as corporations they have an image and overall agenda they are allowed to promote as private entities, not journalistic entities. So if they allow content contrary to their corporate mission that allows attacks to their interests, they have to deal with the consequences.

Thus, why any search or shopping website or social media site is NOT a journalistic entity and simply a place to pay for advertisement of your product, content, or website.