This right here is the correct answer. The average American is a little bit stupid but generally speaking, the reason why we are is because our education system sucks shit and we are bombarded with conflicting misinformation from literally all angles, constantly. Foreign actors lie to us just as frequently as our own government and corporations do. Truth has become a precious and rare commodity and is frequently discarded out of hand when it is found because the education system hasn't taught most of us how to challenge our own assumptions.

Most people aren't stupid, they're misguided. As in, led astray, purposefully.