How do you validate I've paid and let me through with a static QR code for something like the metro, or a ticketed event, or even a coffee? How do you know they paid the right amount? I turn and show you my receipt, and you hope it's not faked?
The answer is they don't do that - and they do it the other way around. The user shows THEIR QR code to the merchant (or automated kiosk).
Which means they still need a terminal - and it's going to be slower than NFC.
It goes both ways and depends. The point is there are options and your statement is not correct.
Some merchants, like street merchants or drivers, will simply have their code printed out. You scan it and pay them and they get a notification on their phone or tablet that you've paid. Other places, like at bigger restaurants, have QR screen readers that will scan the purchaser's phone.
Either way, I don't see what you're getting at. The terminal is the phone in many cases, and other cases, there is a terminal in the sense of an integrated scanner system, but why does that matter? For the user it is much more convenient and faster. It's essentially instant, and I have never waited for the amount of time it takes for a credit card or NFC payment method to process. Further, it allows basically anyone to have this method because, again, the terminal is your phone and can be so for both parties in the transaction.
> And NFC works when my battery dies.
So what? You can charge your phone essentially anywhere in China.
> How do you validate I've paid and let me through with a static QR code for something like the metro, or a ticketed event, or even a coffee? How do you know they paid the right amount? I turn and show you my receipt, and you hope it's not faked?
By and large when I've used these systems, the vendor just checks they received the correct amount of payment in their app. It's largely immediate
Only foreign visitors carry cash these days in China in cities in my personal experience :-) Some shops actually don't accept cash at all - so you have to pay a colleague in cash and they'll pay the vendor with Ali or Tencent Pay on your behalf.
China netizen population is estimated around 900 million. So essentially all adults in Urban and many in rural excepting small kids. Generally for the elderly, their kids or grand kids will help.
It's also pretty easy to take an item and walk out without paying. But it doesn't happen. At least, it doesn't happen that much, and I would guess it happens much less in China than in the USA (though I'd be curious to see actual shrinkage numbers).
QR codes seem to have largely supplanted cash and credit cards in mainland China, whatever hypothetical downsides they might have. And the very limited hypothetical advantages of NFC (it's unclear to me what they actually are, but let's grant they exist) don't compensate for the fact that an expensive terminal is needed, so NFC isn't displacing QR codes in the near future.
It doesn't have a bearing on which method is riskier, but it does have a bearing on the idea that everyone is going to be generating fake receipts on their phones.
And, yeah, most places do verify based on another phone.
The answer is they don't do that - and they do it the other way around. The user shows THEIR QR code to the merchant (or automated kiosk).
Which means they still need a terminal - and it's going to be slower than NFC.
And NFC works when my battery dies.