Good analysis. I generally see stereotyping in a development psychology way: It emerges in full bloom in high school age (ages 14-18) and continues for some throughout life.
Teenagers are trying to figure out their own place in the strata and at the time, they often believe the stereotypes presented by their peers [and reinforced by entertainment].
As far as their accuracy goes, well, its like many generalizations: it’s like buckshot hitting a target.
The good thing about generalizations like stereotypes is it’s easy enough to go to a place of higher accuracy, but it’s much more difficult when you are aiming for precision and not accuracy… which is why I don’t watch documentaries.
[they pull you through a very precise chain of logic which ends up with an “inevitable conclusion” that fits the logic of the arguments, but ends you in a place that’s far from accurate.
This is also why for me, logic isn’t king.