The proof of a problem isn't "someone put a gun to my head" - its a meaningful part of our society put behind a rich man's walled garden because only he had enough money to bribe every telecom and buy every competing platform.
Every competing platform? I can think of a few alternatives, starting with this one we are on right now. But some people are still choosing Facebook, and they are choosing it willingly, happy they do not have to pay for it with anything more than some targeted ads...