I disagree. The Peter Principle states that one achieves one position above competency. We have gone around the corner and people, especially women and minorities, can exceed multiple levels of competency.
It’s the highest level of incompetency that they stop at. Once those in charge realize that that employ is incompetent in his new job, he never gets promoted again. Nor does he get demoted. He stays at his highest level of incompetence. Not his lowest level of competence. If that was the case, he would be appointed one more time.
That's true, but the Corollary to the Peter Principle states that one gets to the incompetency position, messes up, and gets promoted... again!