If the conceptual construct is made of concepts, and the power of high-level languages comes from being able to write software in concepts similar to the constr

If the conceptual construct is made of concepts, and the power of high-level languages comes from being able to write software in concepts similar to the construct's concepts... He states that the accidental complexity comes from mapping the conceptual construct to a real implementation. But does that mean he's saying we already know about the essential complexity of a given problem? That doesn't seem the case to me? The way we express the conceptual construct can also be improved, no?