The difference is that for most people their phone is always in their pocket or easy to grab, 24/7. A credit card may be tucked away somewhere for emergencies, or left at home. I lost my credit card somewhere years ago and didn't care when I lived in China because the physical object was irrelevant. It's only when I got back to North America that I realized some retailers still awkwardly require you to present the physical thing.
Just like the phone made wrist watches and portable music devices obsolete, it's also made the wallet obsolete. I agree that both NFC and QR code are equally convenient (although obviously QR codes are more accessible because they work on all phones and no special scanning devices are required), but I think the main issue is with NFC in a card versus NFC in a phone. The phone is always going to be more convenient, because people today are rarely - if ever - without their phone.
Just like the phone made wrist watches and portable music devices obsolete, it's also made the wallet obsolete. I agree that both NFC and QR code are equally convenient (although obviously QR codes are more accessible because they work on all phones and no special scanning devices are required), but I think the main issue is with NFC in a card versus NFC in a phone. The phone is always going to be more convenient, because people today are rarely - if ever - without their phone.