"We" as in a total society or specifically as men do not stack any of these specific expectations on young girls. Young girls do this to each other. The influencers are girls and followed by girls. Instagram is girl territory and all the social gossip around it is girls.
They're not trying to win boys' approval, instead girls' approval.
Social ranking amidst young girls is natural behavior, what changed is that the limits of the physical world that kept it in check were removed, and now we see the fly-wheel effect.