Yes, actually, it does. Payment processors like Stripe (technically, an ISO) and its merchant acquirer partners must pass through most of their fees as interchange to the bank which issues a card. Those fees are much higher here in the U.S. versus Australia, where they are regulated.
A typical U.S. payment processor charges ~2.3%, of which the processor retains 0.5%, 0.1% goes to Visa, and the remaining ~1.7% goes to the card issuer. (This averages out card-present and card-not-present sales across all sizes of merchants, and is just a rough estimate, so no judgement on Stripe's fee level, which is reasonable for a simple blended rate for e-commerce.) All of the processor's product development, marketing, operations, profit, etc., have to come from that small 0.5% margin. (That said, it's still a good business, with 50% margins at scale.)