this is especially important when you want to do line-breeding and want to improve a gene this way.

for example: you get a nice male fire and a nice female fire and breed them, and you hatch a nice male super fire.

now you take that nice super fire, and breed it to 3 selected nice normal females. you get a ton of fires, nothing else, all hatchlings are single-gene fire. and you pick the best of the best, you produce 20, you sell 18, you keep two. selective breeding is about repeating this process, line-breeding adds inbreeding to the equation. with inbreeding, you can speed it up and fix certain traits, but you risk adverse effects like inbreeding depression.

all breeders do selective breeding, that is clear, but many breeders put their own limits on inbreeding. but anyway, for a breeder, supers are really useful, when you want to make fireflys you breed a super fire male to 2 or 3 super pastel females, and all of them are fireflys. 100%. and now you can choose your holdback firefly and sell the others. a breeder with many supers can produce combos on demand. people want mochis? lets put the super enchi to some super mojave girls. people want mystic potions? its nice to have a super mystic male in that case, pair him with anything mojave you have.

supers bring consistency. if you want to get a 5-gene-world-first-whatever, supers are not for you, better just breed a pewter fire to a yellowbelly enchi and hope for the odd gods.