Kids who watched the Simpsons when it was at its peak of popularity have kids of their own now.
When I went to my 25th HS reunion, which was age 43, I was amazed at how the women still mostly looked young and almost exactly the same as they did in high school, with just a few exceptions. The men, myself included, had all put on weight and looked a lot different. I was much more likely to need a name tag to let me know who a guy was than a girl.
Not much change at all by the 30th (48 years old).
At the 35th (53) the women started really showing their age and suddenly I needed name tags for the women too. And for the first time, in both sexes, I saw people who "looked like grandparents" to me. Not the majority, but certainly a decent number. (And of course some of them actually ARE grandparents).