At least you were able to board your flight, however annoying the experience, many others cannot when their card has changed or they do not have it with them.

I see this as an increasing issue and although payments that go through 3d secure are supposed to be immune to this I have heard other examples recently when that has not been the case. QR are certainly not alone in requiring this, and as far as I understand things it is due to anti fraud measures required by the card brands at a global level (Visa, MasterCard) rather than individual countries, although some airlines clearly do not require the verification.

This can be one area where paying on the airline website via a third party payment processor (PayPal, Alipay, WeChat, etc) where the card number is hidden from the airline can be very useful as they have no concern to validate a card number and the contract for payment from the card is not directly with them. The other option is to purchase via a third party OTA where the whole transaction is with a third party although that has other disadvantages.