Disagreed. Maybe with some people, particularly of a very suggestible type, but I know dozens of young people in my own family and those close to us who don't take the majority of the preening crap thrown at them by highly edited social media profiles, reddit posts, youtube channels and so forth nearly as seriously as you paint the situation.
Sure, it might cause some insecurities here and there, but mass media always did this to teenagers and adolescents. At least in the modern version they also get plenty of doses of normal reality and often pretty interesting DIY educational stuff from people in the digital sphere, because just as it shows doctored images and life stories, it also often lets slip through a great deal of crude realities that teen magazines and other such media in the pre-internet past never even let peek out.
I know that exaggerated hating on the power of social media is popular on HN (among people who often tacitly support this very industry with their work no less) but for the most part, the adolescents I do know live a life in which they do usually know how to use their brains to distinguish the toxic and falase from the more or less normal and rational.