I am currently studying COM. I found that COM DLL is kind of built upon the traditional DLL infrastructure. When we build COM DLLs, we still rely on the traditional DLL export methods to lead us to the internal COM co-classes.

If COM is for component reusing at the binary level, I think the traditional DLL can achieve the same thing. They both expose functions, they are both binary, so what's the point of turning to COM approach?

Currently, I have the feeling that the traditional DLL expose methods in a "flat" manner, while the COM DLL expose methods in an "OOP" hierarchy manner. And the OOP manner seems to be a better approach. Could this be the reason why COM prevails?

Many thanks.