Eningeers get tons of actually effective training and schooling. Alot of people probably spent at least 4 years in school learning a science where there are right and wrong answers. It's easy to evaluate engineers. Most managers seemed to get to that role by accident, or because they knew the right person. I think there's way more underperforming managers. Managers aren't going to school for years, even when they do the degree they come out with feels useless.