I also wonder if some failures of human rationality could be counted as a weak form of wireheading. Self-serving biases, confirmation bias and rationalization in response to cognitive dissonance all create counterfeit utility by generating perceptual distortions.

I think those are good examples how human brains build (weak) delusion boxes. They are strong enough to increase happiness (which might improve the overall performance of the brain?), but weak enough to allow the human to achieve survival and reproduction in a more or less rational way.