Foster Kramer wrote a hell of a piece explaining why we ought not to trust Facebook with the stories we see appearing on the newsfeed. Here are two tidbits but please read the whole thing:

And as smart as you think the people who run Facebook are, trust us when we tell you that they are far, far, far smarter than you could imagine (and if not the people, then definitelythose algorithms). 

They understand human psychology to a stunning degree, which is how they've been able to capitalize on it for the last few years. It's why Facebook is filled, mostly, with the things you agree with, or are seemingly helpless against clicking on. But because you're a human being, something about it probably rubs you the wrong way. As it should! You're a human, and not a hamster doing a stupid pet trick, which is what Facebook has turned both readers and publishers into. Credit where it's due: They're that good. And yeah, fake news is a problem—but before we learned about it being a problem, where Facebook was concerned, it was a feature.

And

So! Facebook created the newsfeed, and then turned to publishers/media outlets, and said: Guess what? Everyone's on Facebook. You want a piece of the action? You're gonna play ball with us. You'll put share buttons on all of your stories. You'll participate in our Facebook Instant Articles program. You'll advertise with us! When we tell you that we're going to start promoting video over articles, you're going to start making video. And then when we tell you what kind of video, you'll make that video too! And if you don't want to play ball, fine. Your competition will.

[Source: The 2018 internet resolution everyone should have: Bring back your browser bar]