There are way too many facets of intelligence to adequately test or benchmark average intelligence, so the whole pursuit is moot. All you can do is benchmark General Intelligence and that doesn't nearly encompass enough cognitive areas.
Just because a person does well in school doesn't mean they are geniuses. Some people are good at retaining or processing information. Ask said person to create something entirely new based on what they have learned, only a small few would be able to apply their knowledge. On the same token, just because a person does poorly in school doesn't mean they are stupid. One of the smartest people I know never took school seriously. He just wasn't stimulated by what he was taught. These days, he's a millionaire at 24 giving stock advice to Fortune 500 companies. Would you be able to call him a bumbling idiot with a straight face?
The purpose of Academics is to set people up for the real world by teaching them important life skills and history, at least in theory. Some people learn these skills in their own way or are autodidacts. School is not a glorified intelligence test even though some people seem to think it is.
The only way a true intelligence test could exist is if every single aspect of cognitive functioning were covered. This includes logic, reasoning, memory, emotional, creative, spatial, linguistic, musical, psychological, physiological, and much more. But in order for that to exist, there would need to be finite boundaries to define and measure every category. That alone is impossible because creativity theoretically has no limit. And you can't deny that creativity is a cognitive ability because if it weren't we'd all be able to create works of art effortlessly. I seriously doubt this test will ever happen as there is no practical application for it in modern times other than general curiosity and bragging rights.
