I get it. High heels are hot. Tighten the calves. Lift the butt. Taller. More step on me energy. They’re hard to walk in. All valid points.
However, the sound of heels, its like an insecure toddler stomping down a hallway. Just imagine a normal pair of shoes doing the heel - toes slap. Clop clop clop. Cringe.
I would guess the heel part has to be rigid and usually the surface area is smallish and the bottom surface of the heel probably can’t be too squishy either. I am guessing those things make at least the heel part louder. I have never worn them or studied them at length so maybe I am full of it lol. I have had mens dress shoes that were pretty loud too due to stiff materials.