For the grandparent, cash back cards work by charging a higher percentage to the retailer and they haven't seen much traction or support in many European countries. Effectively in the long term they simply raise prices and give a greater cut to the card processor, theoretically they're overall a bad thing for consumers.
https://www.americanexpress.com/uk/credit-cards/platinum-cas...
For the grandparent, cash back cards work by charging a higher percentage to the retailer and they haven't seen much traction or support in many European countries. Effectively in the long term they simply raise prices and give a greater cut to the card processor, theoretically they're overall a bad thing for consumers.