Little kids do, then they're taught "that's not for boys/girls." Society conditions kids since birth that they have to do either "girl things" or boy things." Drag Queen Story Hour is good because it says, bump that, do what you want.
The reason Republicans are obsessed with trans people and drag queens now is to distract from economics, but conservativism as an ideology and movement has always been against these things because they question the patriarchy. Part of conservatism is the idea that gender roles must be enforced. But drag queens, gay people, and trans people all debunk the argument that we need enforced gender roles to have a functioning society.
Most of them don't.
They're not. Drag Queen Story Hour isn't about sex, you creepy weirdo.