It is an insurance policy then. Have you calculated how much this insurance cost you? Credit card fees, the inevitable 'forgot to pay it off' etc.
Indeed if say an IT problem occurs and they can't do that transfer under UK law they eat the fees incurred. "The customer must be made whole".
As to fees, the merchant doesn't have to accept cards, as we see with Amazon, if they don't like the fees. Why should ordinary consumers care? When we were part of the EU the cards couldn't charge excessive fees, now Brexit allowed them to unlock this potential source of profit.
Never paid a penny in fees or interest in over 15 years.... and an annual statement of fees (issued by law) informs me of this fact each year.