That being said, I've seen some powerful arguments against facebook already: the newsfeed algorithm, for example, is my most important one. It should be required, by law, to be a dumb feed.
Outside of that we have to look at the evil companies that you speak of otherwise, and why we don't speak out against them, and I would draw that the reality and rules that society lives under are distorted by the existence of social media, which isn't necessarily a bad thing, many changes need to occur, however I argue the things that make facebook addictive (getting likes), and thus valuable, are the things that encourage the worst societal behaviors and extremism, making it impossible enough for society to compromise enough to do something about those bad actors. You demonstrate the power of getting likes by the fact that you used a throwaway account for your comment.
I don't think that social media can effectively work unless it is stripped of the profit motive.