Now explain why somehow our most important trait makes us dominant from a biological point of view.

It allows us to accomplish far more than would normally occur based on our biological limitations.

Your problem is trying to argue based on an academic definition (that is not universally defined) against the common usage of the word dominant and doing a piss poor job of making that clear. Like when someone uses the lay version of theory and then arguing against it based on the scientific definition of theory without making it clear which one you are using.