Earlier quoted context omitted.
Furthermore, everyone, regardless of whether they are using a credit card, is paying for this in the form of higher prices (unless the vendor has separate cash prices...)
Higher cash prices are a violation of the card-holder agreement.
> Higher cash prices are a violation of the card-holder agreement.
I think what you are meaning is “higher card prices are a violation of the merchant agreement” – so a merchant can't offer different prices for cash payments to account for differences in processing costs or they risk losing their merchant account with the card/payment processing company.
In some places this is no longer legal¹, you'd have to check your local legislation to know what applies in that regard where you are.
Also the reverse, offering discounts for card use rather than cash², is illegal in some places because it is unfair to those without cards⁴.
--
[1] so card processing companies can't (legally) punish merchants for offering a discount for cash
[2] usually because the merchant gets a kick-back from the card payment processor, though sometimes these days it is because cash has become the minority payment method³ and vendors would rather only deal with one so want to further discourage cash
[3] it is worth noting while discussing potential costs or kick-backs for card payment processing, that for businesses the act of dealing with cash has associated admin and/or costs too
[4] which is disproportionately the disadvantaged, because they find it harder to qualify for any card, or can only qualify for one with a monthly charge that they can ill afford