There was very strong stereotyping of children's toys in the past - have a look at any ad for a Hornby toy train set from the 1950s, and it will have a little boy in short trousers with a Fair Isle pullover and a dad with a pipe clenched in his teeth - guaranteed!
Toys'r'Us etc had very distinct separate aisles of Boys Toys and Girls Toys [yes, minus the apostrophes]. The Argos catalogue rigidly divided boys' and girls' toys into different sections.
[The last Argos catalogue I saw had removed the labels 'boys' and 'girls' , but the girls' toys all had pastel colours, and the boys' toys all had dark colours! flames! exclamation marks! - stereotyping is subtle....]
In the early 1990s I actually saw a woman in a shop tap/smack a little girl's hand away from a toy car saying 'NO, that's for boys!'
There was, as posters have pointed out, a period around the 80s when the challenge to gender stereotyping of children had some effect - kids with similar haircuts, similar clothes with dinosaurs on them, similar Kicker-style boots.. a brief period when kids could just be kids.
What we are seeing now is the result of a huge backlash against that - pink, glitter, fairies, princesses, butterflies, came back with a bang to reassert the girliness of girlygirls, and the boys will be boys-ness of real boys.
The Disney Princess franchise - see? commercialisation - was relentless in the mid2010s, there's even a 'National Princess Week' which was started in 2012.
The reinforcement of gender stereotypes which is evident to anybody who grew up in the 70s or 80s didn't just happen accidentally, it was a backlash against the limited advances that feminism had made.
The return of gender stereotypes has been seized on by the trans movement - if you're a boy and you like glitter and princesses, maybe you're not a real boy and have you thought about transitioning to being a girl instead? - and the tradwives movement.
All rocket-fuelled by social media of course.