For some subsystems, sorting is a highly important function. Sorting the primitive render calls so that they render front to back for opaque objects can have a massive impact on GPU performance, so it’s worth doing. Sorting the primitive render calls so they render back to front for alpha blended objects is usually a necessity. Sorting sound channels by their amplitude over their sample position is a good indicator of priority.
Whatever you need to sort for, make sure you need to sort first, as usually, sorting is a highly memory intense business.