Many cards carry no annual fee and still pay rewards, which raises the question of what a fee actually buys. It funds a benefit package that transaction revenue cannot support on its own, and it filters who applies.
Interchange sets a ceiling on free rewards
Card issuers earn a share of each transaction from the merchant side, and that share is the main pool from which rewards are funded on a no-fee card.
Because the merchant share is capped by network rates and competition, the rewards that can be paid out of it are bounded. A card cannot indefinitely return more than it collects.
Premium benefits such as lounge access, travel credits and insurance protections cost the issuer real money, and they exceed what ordinary transaction revenue supports.
The fee is a subscription to a benefit package
An annual fee converts part of the card into a subscription product with a predictable revenue line that does not depend on how much the customer spends.
That predictability lets the issuer contract for services at scale, since it can estimate participation and negotiate with airlines, hotels and insurers accordingly.
Benefits delivered as statement credits also cost the issuer less than face value in practice, because a meaningful share of cardholders never redeem them.
Fees select the customer the issuer wants
A fee discourages applicants who would use the card lightly, since the fixed cost only makes sense against substantial spending or heavy use of the benefits.
The customers who remain tend to charge more, which generates more merchant-side revenue and makes the whole account more valuable regardless of the fee.
Higher-spending customers are also more likely to fall into interchange categories that carry better rates for the issuer, which improves the economics further.
Fee cards and interest cards are different businesses
Some cards earn primarily from interest charged on revolving balances, and those cards are designed around borrowers who carry debt month to month.
Premium fee cards are generally designed around customers who pay in full, where the revenue comes from fees and merchant transaction share instead of interest.
The two models compete for different behavior, which is why the pricing and the rewards structures look so unlike each other.
Whether a fee is worth paying is arithmetic, not judgment
The value of a fee card depends entirely on which benefits a specific person would actually use, valued at what they would otherwise have paid for them.
Credits for services someone does not buy are worth nothing to that person, however large the advertised total, because the value only exists on redemption.
Comparing the fee against realistically used benefits, rather than against the headline package, is the only calculation that reflects a particular household's situation.