Let's say you have a professor in some mechanical engineering department that teaches a course in thermodynamics or machine design (fatigue analysis, FEA, simple mechanisms), is this guy more intelligent or knowledgeable than someone who has worked as an engineer for the same amount of time?

I know some people say "those who can't do, teach", but is that really true? Is some rando engineer employed at some rando company a better engineer than an engineering professor?