To summarize biases further, in one word: Incompetence.

Lab results confirming cognitive biases come from testing small groups of students (up to 200). Among other things, it means: (1) respondents with similar background, so we can't generalize (2) respondents don't care about outcomes, (3) tests are synthetic. Plus publication bias and other standard issues.

These results are themselves a sort of confirmation bias.

Mistakes in real life happen when we don't know what we're doing. If a person can learn, he'll discover systematic mistakes. But that comes with domain experience, not cognitive science.