Smart managers and leaders know that people have different values, abilities, commitments, speeds, personalities and all kinds of varying qualities – so they don’t insist on treating everyone the same.
Instead they find people whose qualities and talents are best suited for the particular positions, and treat them in varying ways to get the best out of them.
Performance variations between employees is expected and accounted for with variations in pay. The only way to get uniform performance from people is to push the bar down to the lowest common denominator. If you want an environment where people do their best, you can’t demand equal performance.