I'm sorry to report that you're looking at that tech through rose-tinted glasses. I remember electronic systems that would routinely fail to properly scan the mag stripes. I remember all the people working retail who had special tricks to try to get a card to scan, which would help maybe 25% of the time. I remember cards becoming demagnetized for random reasons and becoming useless. I remember when merchants would have to take a physical carbon imprint of the card, and would have no idea if the card was even real until the paper was processed, days or weeks later.