Most "normal" suspension bushes are designed with inner & outer sleeves with rubber bonded to both interfaces through moulding process. Its not the metal that pivots, its the rubber that torsionally twists when the wheel-control arm moves up-down. The thickness, geometry & composition of the rubber determines the stiffness rate of the bush which changes how the car handles & feels i.e. they are a lot more than just absorption points.
Some of the best handling cars out there have rubber composition in the ~55-60 Shore hardness region for comfortable ride & handling. Gives you a perspective on what kind of a bone jarring ride 90 shore hard poly bushes would give.