I think what the parent meant was that “true” 10x engineers can apply their skills to a wide variety of problems, and it isn’t just applicable to a narrow problem domain and/or for a very short period. This makes clear he isn’t talking someone who just happens to be specialized in a specific codebase or one specific problem, for example.
Most companies won’t have structure to accommodate such generalists anyway so they will get pissed or bored and quit so you probably should look for “fake” ones then.