Why does it have it?
Yes, it increases range; but even if you aren't on a very long segment it is of use, because it optimizes CG for lowest cruise drag, thus lower fuel burn.
(Funny how every decade or so someone new discovers this bit of aeronautical enlightenment. I recall a UAL F/E getting a nice bonus 40 years ago for suggesting a standardized loading routine toward the aft end of the CG envelope!)