This question is amazing tbh, simple but never been asked.
Range plays a part in pax. I like to think of it like real life, the farther away, the more realistic it is to fly then drive. Take SFO-OAK, you will expect most to drive(I know those lazy business men, but still). But SFO-YXD(Edmonton, Canada). Even tho OAK has more passengers, you will see a increase of pax and amount they will want to pay. SO, the pax of AM are realistic or...
Range plays a part in pricing. Each NM will increase the amount pax will pay by $X.XX. It may not play a big factor in close range airports, but as you start venturing into the farther out places, you will see that you can increase the amount of cash to sell seats as the nm to $$$ factor has more nm to increase that $$$. Say SFO-OAK is 20nm, and that each nm increases how much pax will pay buy $.10. So your looking at the regular price that you can get from that airport to this airport plus an added $2 for the distance. This may not seem much, but when it comes to 500+nm your looking at $50+ you can have them pay cause of the range. So In long distance flights, it may not be the airports trafic doing the key profit, but just how far they are.
*nm = nautical mile **the "1nm= $0.10" was an example.