Lots of twerking and pre-teen US airhead types doing make up tips
This is the root cause, I think. Setting aside the parents who genuinely don’t think there’s anything wrong with this behaviour for young girls (or the equivalent is for boys - I don’t have a son of that age so don’t know), parents seem too reluctant to call out this stuff for what it is, like @KERALA1 just did. They can’t find a way of expressing that this behaviour is undesirable and not what they want their daughters to emulate, without seeming to criticise the parents of their kids’ friends, who may also be their own, who allow it and therefore look as though they’re condoning it. People seem okay to go with “my house, my rules” for outright bad behaviour in small children (hitting, kicking, swearing) but struggle when their children are old enough to construct counter arguments. So they give in.
In my opinion, it’s a general lowering of standards, combined with political correctness. Adults can’t say “no, because I’m an adult and because I say so” anymore.
There are so many ways to find a middle ground, but they all take time, thought, and lots of energy to monitor and reinforce and review, for each child.