If you want a truly frightening picture of what a monstrosity Facebook has become, and how it poisons free speech, I recommend “Zucked” by Roger McNamee. McNamee was one of Zuckerburg’s first mentors and has been a presence in the world of internet development for decades.
He too thought that the concept of creating a public forum for people to share data was amazingly great, until it turned into a nightmare monopoly that monetizes personal information without out permission (even if you’re not on FB) and has almost accidentally, through greed and apathy, morphed into a principle factor in destroying our democracy.
It’s not an exaggeration, nor a doomsday message. It’s a moral lesson with a ton of practical suggestions for correcting this error. He focuses on FB because he knows the executives there, but he says the same applies to Google and Amazon. To me, this issue of technology perverting our society is as critical an emergency as climate change.