Can Bayesian Models of Cognition Show That We Are (Epistemically) Rational?

According to [Bayesian] models in cognitive neuroscience, says a recent textbook, the human mind behaves like a capable data scientist. Do they? That is, do such models show we are rational? I argue that Bayesian models of cognition, perhaps surprisingly, don't and indeed can't show that we are Bayes-rational. The key reason is that they appeal to approximations, a fact that carries significant implications. After outlining the argument, I critique two responses, seen in recent cognitive neuroscience. One says that the mind can be seen as approximately Bayes-rational, while the other reconceives norms of rationality.