Sorting NFT's by rarity score would help give a quantifiable value marker for people to choose which NFT's they would like to purchase and benchmark the value of any given price against. Right now, we can only sort by arbitrary traits and properties which are hard to truly value. However if you could sort by rarity score and see, for example, that NFT rarity ranked at #40 is on sale for half the price of other NFT's rarity ranked in the 200's, one could begin to more accurately assess pricing.