Could it simply be that Generation Z is accustomed to seeing women compete in wrestling, boxing, and mma, making fights between untrained women less relevant? Today, in high school, that cute girl in algebra class might be on the wrestling team or training in bjj at a dojo downtown.
I think I would actually flip the order of this sentence. As a child of the late-1970s/early-1980s, my observation is: That gritty girl training in kickboxing at a dojo downtown is today also
> getting an A in AP Algebra,
> has a 4.25 GPA (out of 4--don't ask me how that makes any sense),
> runs cross-country and is All-District,
> is Treasurer of the Tech Club,
> volunteers at the pet shelter next to the downtown dojo,
> and is applying Early Admissions to Cornell. If she doesn't get in, she's doing the Honors College at University of Indiana, because of their high placement rates in summer internships.
In the 1970s and 1980s, that same girl was every bit as high-energy and striving, but her outlets were to work nights and weekends at a restaurant, using the tips to buy a reliable car and dating a boy who was already "done" with high school, altho whether that was because he had graduated or dropped out was a little fuzzy.
In fighting:
> if she did it back then, it was with acquaintances of the GDE-man/boy,
> if she does it today, it's over sarcastic flaming of her otherwise flawless Instagram page by a jealous less-accomplished classmate.
So, it's not that the accomplished girls are training in defense/combat sports. It's that the driven girls have more outlets to express their talents and energies.