Why are there so many underage girls?

I understand that 13-16yr olds need to track periods too. That's totally cool. I also realize that they may have questions theyre embarrassed to ask friends and family so they ask here in a mostly safe environment. Again it's cool. But why am I seeing alot alot of underage girls posting TMI pics asking to rate their bodies such as boobs/ass?? Or talking about sexually explicit content and borderline soliciting themselves? I can't be the only one that thinks this is absolutely insane.