Probably starting in the sixties kids were portrayed as the smart ones and adults, particularly dads were shown as stumbling idiots. Quite a change from “Father Knows Best.”
You still had Family Ties and Mr. Belvedere in the eighties, and even Roseanne, where John Goodman’s role portrayed a slob, not an idiot. Dads were still mostly okay up until the nineties.
Dumb dads didn’t come in until at least the late 70s.
(To be fair, they had had decades of dumb moms before then, but dads are stuck in the role now.)
Remember the popular “The Life of Riley”.
“In all of the show’s incarnations, the comedic plotlines centered around Riley himself, a gullible and occasionally clumsy (but big-hearted) man, and the doings and undoings of his family. Riley’s penchant for turning mere trouble into near-disaster through his well-intentioned bumbling was often aided or instigated by his arch best friend/next-door neighbor, Gillis.”