QR codes have been available for a while. Square helped do payments through credit cards. At that time payment via QR codes was cumbersome, and not adopted. But

QR codes have been available for a while. Square helped do payments through credit cards. At that time payment via QR codes was cumbersome, and not adopted. But I think it depends more on the consumers and local economy. US was anyway using credit cards a lot. Asia preferred cash, for smaller transactions.