Of course wind speed is a direct measure of the instantaneous force exerted against one spot. The additional dimension of energy content is linked to the area covered by the storms, subject to those wind speeds. The bigger the pinwheel, the more energy to crank it to a given speed. Irma's 400 miles wide, Andrew was an energy runt concentrated into such a small space that at one point it surged to cat 5. The article has dimensioned photos halfway down, and Andrew was half the physical extent of Irma. Extent in time matters too, just ask Houston.

My point was really just that the estimated energy content of a hurricane seems to give a quick synoptic picture of the potential damage a storm can cause. Just like more megatons make nukes more destructive, more terajoules make hurricanes more destructive.