Here's the problem with Idiocracy:
Someone still makes cars. Designs them, builds them, ships them. Someone still designs stores and buildings, and runs the factories that fill the stores and buildings with products. Someone still designs and makes clothing. Someone still creates and produces television shows and movies. On and on, etc, etc. Now, they may do all these things poorly, but they still do them. I don't know about you, but I can't do any of that, even poorly.
So in this futuristic world populated entirely by mouth-breathing morons, there are still vast amounts of the population
smarter than me