It's perfectly possible our heuristics are muddied beyond necessity in order to generate variety in action, so as to reduce risk to the unknown for the species - even though it would cause a minority of individuals to consistently make sub-optimal choices. From a speculative standpoint, it's easy to find examples of people doing things that we consider 'stupid' but it pays off because of some unlikely event occurring in coincidence.

Reality has a lot of unknowns. There is no perfect model that could account for that. It's possible being hyper-intelligent (beyond our current ability) is (or was) a disadvantage for the species