I had never heard of the Dunning-Krueger effect before. It matches what I have been using for a long time. My version was that some people are so dumb, they don’t know they are dumb. I didn’t realize I was clinically correct.
It explains a lot of what is happening in the US today.
Also, this seems highly probable:
Anosognosia, also called “lack of insight,” is a symptom of severe mental illness experienced by some that impairs a person’s ability to understand and perceive his or her illness. It is the single largest reason why people with schizophrenia or bipolar disorder refuse medications or do not seek treatment.