And while THE FLINTSTONES was clearly a HONEYMOONERS rip-off, wasn't THE JETSONS a FLINTSTONES one?
Not really -- there are some clear similarities, but it's not a direct imitation, more a parallel creation. This essay
says The Jetsons
was inspired more by the visions of optimistic futurism that were in vogue at the time, "a projection of the model American family into the future." Which is rather different from the more dysfunctional Kramden and Flintstone families. And George Jetson himself was based on his voice artist, George O'Hanlon, and his trademark character Joe McDoakes
, a hard-luck everyman who'd appeared in a series of comedy film shorts in the '40s and '50s.