Optical illusions (there's also physical ones) are often demonstrations that the problems aren't solved in humans either; they're just "things that work sort of, some of the time, with caveats about how you define 'work'".

More so if you include reasoning illusions like people being more scared to catch a plane than drive a car or thinking that a lotto ticket is a good investment.

Human intelligence doesn't really meet intuitive definitions of human intelligence. But it does work well enough as long as you ignore all the times it doesn't.