Facebook knows Instagram is toxic for teen girls, company documents show
Is it Facebook / Instagram's fault or us as a culture? As a culture we adore beauty, wealth, power...Facebook seems to be just a platform where our natural desires can have a play. Facebook hasn't created this impossible beauty ideal, it was created long long ago by Hollywood and the fashion industry. Facebook just makes it super easy for people to become obsessed with something by "connecting" with it. 
It used to be that 40 years ago you watched some supermodel in a commercial for 20 seconds and she was gone. The novelty with the internet is that now you can follow this supermodel and get dozens of alerts a week about her.
If it's not Facebook it's gonna be TikTok or something other platform.