The point isn't that a humanoid robot walking is less efficient than a human walking, is that moving on a wheel is not the same thing as walking. For example, using wheels is not only less efficient it is barely usable for climbing rocks, going up the stairs and many other surfaces that makes the comparison irrelevant.
You could say that a robotic gun is much more efficient than a human in killing, that's another easy easy comparison of different tasks where robots win, but it totally miss the point.
You could say that a robotic gun is much more efficient than a human in killing, that's another easy easy comparison of different tasks where robots win, but it totally miss the point.