Title has become mangled, should be "The reasons why people become incompetent at work". TLDR, the Peter principle: "Every employee tends to rise to his or her

Title has become mangled, should be "The reasons why people become incompetent at work". TLDR, the Peter principle: "Every employee tends to rise to his or her level of incompetence – Laurence J Peter". A quote I didn't know, he apparently also said that competence is in the eye of the beholder.