I imagine the emergence, spread & increasing popularity of cable TV, affordable home video players & tapes, in the 80s & 90s were a major factor, and with them the proliferation of often sexist & trite media and "children's programming" meant for little kids (by companies like Disney & Saban). And of course the introduction & popularity of home video games. Along with parents no longer setting any limits on the amount of time a day kids could spent staring at screens.

Used to be, there were only a handful of TV stations in any market, and kids at home could only watch the TV shows & movies that adults running the few stations/channels in their area decided to broadcast, and only at the time when that particular content actually aired. So kids would get to see their fave TV show for 30 minutes once a week, and their fave movie on TV once a year. Even kiddie fare that aired daily or most days, like cartoons or Romper Room, only aired for 30 minutes to an hour or two at one time or select times of the day. But in the 80s and 90s, more people got cable, the number of cable channels greatly expanded, and parents could also tape or buy their kids' fave movie and shows, park their tots in front of the TV set and let them watch the same material over & over. In such a situation, the imagery & messages of the mass-produced media consumed by young impressionable minds was bound to sink in deep, and to loom larger in their psyches than what those same little kids might have observed in and of the real world. If, that is, they had much chance to to observe in the real world - a big if because at that same juncture in history, kids became far more indoor-bound homebodies than ever before.

Which brings us to another huge shift that occurred in the 80s, in the US at least. The 80s marked the turning point when kids en masse stopped spending a lot of time, or any time, outside the home unsupervised and unchaperoned by adults. The highly-publicized and tragic cases of Etan Patz and Adam Walsh put and end to the sort of "free range childhoods" that kids of earlier generations had, when children in suburban, urban, small town & rural settings alike all spent a great deal of their/our free time on our own amongst other kids without any adult supervision & input - and when it was customary to walked to school or the bus stop on our own too starting in kindergarten.