Humans differ greatly in achievement even though potential as measured by intellectual capacity is small.
The competent tend to regard their success as luck. The lucky tend to regard their
success as a product of competence.
Humans perform grandly in matters of technology but are wimps in performance in matters communication and reasoning together.
Technology is pretty much cut-and-dried. Demonstrable. Mechanistic. Repeatable. Consistent. Relatively few variables.
Communication/reason is very fuzzy by comparison. Highly dependent on context. Full of feints and parries, twists and turns, subtlety and nuance. A larger number of variables. Not nearly as repeatable or consistent, often a matter of opinion.
Enough variation in that to explain why humans can be pretty savvy at one and pretty sloppy at the other. I think this is probably a logical/predictable outgrowth/consequence of evolution itself -- the mind is generally geared to solve relatively concrete problems, where "concrete" refers to relatively obvious cause/effect, acting on information provided to the brain through the senses. And that's only valuable, evolutionarily speaking, insofar as it confers a survival/reproductive advantage. It doesn't take a huge amount of computing power to get a survival edge -- insects aren't that bright, but they do just fine navigating their way through the environment. All the other stuff that humans get so attached to, as interesting as it is, is mostly sideshow as far as evolution is concerned. Ultimately, it either survives long enough to reproduce or it doesn't.
That's my take, anyway. For whatever it's worth. Judging from the import/value of most of what I say, it's free and worth every penny of it.