I’m not sure I’d even count that 2%, in that the cow’s hide is coming off as part of the slaughtering process, regardless of whether it’s used or not.
Intent matters in this case.
Right, but cows where you don’t harvest the hide would still be slightly less economical than cows where you do. And the owner of a cow to be slaughtered surely intends to wring out every cent of value they can from it.