> Businesses raise prices to account for interchange fees

Agreed, which makes the picture even worse for those low income people. Even poor people are guaranteed to occasionally pay the "rich person tax" included in the prices of some of the products and services. At least until some AI pricing starts changing the price real-time based on the buyer's estimated wealth (sort of already real).

> So they are essentially is paid by the consumer.

Not from a bank's perspective. Only in the sense that prices are higher between the seller and buyer.

> If we outlawed rewards credit cards (by capping interchange fees), everything would likely be slightly cheaper.

I don't agree on the second point as a blanket statement. When Epic game store lowered its fee not a single game got cheaper for the buyers.