With my ,"Pay by Phone" it creates a different card Account number to the card account I am paying by. Also I choose which card account is the preferred one to use.I agree, I think the phone gives out the same code as the card. I looked at it once, I think it meant I needed to get the phone out open it, open banking then use the phone. So no advantage on using a card.
I have seen lots use them in shops, but they are prepared before the checkout, so no problem.
John