The issue is you literally cannot be an engineer if you don't know how to build things. On the other hand, there are plenty of managers that do not know how to

The issue is you literally cannot be an engineer if you don't know how to build things. On the other hand, there are plenty of managers that do not know how to manage people, that do not even know what is expected of them. Should they optimize for cost? For productivity? For employee happiness? Competent managers are a minority. They tend to rise quickly, leaving the inept ones to run the day-to-day.