The entire domains of boys toys and girls toys diverge. Previously often one set of toys was sold for and used by boys and girls alike. The play differentiated along roles but still overlapped. But ot any longer. I wondered: Why is that?

I think I'm seeing the opposite (in Brazil). I see a lot of for-girls versions of toys that used to be made for boys when I was a child. Like RC Barbie racing cars, or pink Nerf guns with matching fashion accessories. Traditional girl toys also look more varied than they used to be (e.g. horror-themed dolls).