I certainly think there are individuals within our species whose cognitive algorithms are performing near-optimally. I just also have very good reason to think I can develop some algorithms that are better for certain tasks than the ones I consist in: I think there's sometimes more information in our sensory data than we take advantage of, and I think that better algorithms could tie together sensing and decision-making to obtain better data more often. Our brains "bite the Bayesian bullet" a bit too hard, accepting noisy data as-is and just making whatever inferences are feasible, rather than computing how to obtain clearer, less-noisy data (which is why we developed science as a form of domain knowledge rather than as an intuitive algorithm).