A card can attract USERS by increasing the rewards it offers -> and charging MERCHANTS for the reward.
So visa infinite cards might charge a much higher swipe fee to a merchant, and then make available cash back + first party car insurance + lots of bennies to the holders of these "elite" cards.
They justify this to merchants by claiming that these "elite" users spend big bucks.
The reality - if users of cards were charged the actual swipe fee their card incurred -> they would push for SUPER low fees or switch to debit cards.
Many lucrative business depend on the person picking the service not being the one paying for it or the kickback going to someone other than one paying.