I do not pretend that I know either, to be honest. That said, there is "For payments over €50, cards were the most frequently used payment method.", which mean

I do not pretend that I know either, to be honest. That said, there is "For payments over €50, cards were the most frequently used payment method.", which means they primarily use cash below 50 EUR, and you cannot do much illegal purchases with 50 EUR, it is such a small amount.