Consumers pay. One way or another. Sooner or later. And upstream costs flow down hill to the consumer. As for cash v rewards, the best way I've seen it said is

Consumers pay. One way or another. Sooner or later. And upstream costs flow down hill to the consumer. As for cash v rewards, the best way I've seen it said is: Rewards don't earn interest. So in general - due to inflation - the longer they sit, the less they're worth. To your point, cash back gives you the opportunity to invest / earn interest.