Cofounder of Lopay here - we have the same mission: offer free payments to businesses, but we're working with existing networks to do this. QR code payments are particularly hard in countries like US and UK as you're trying to change consumer behaviour. I tried doing this in 2014 and again in 2019 - both failed to gain traction (aside from during COVID). In the UK it's possible to accept card payments for 0% via Lopa…
QR codes feel like such a step backwards compared to NFC. The UX with current mobile OSes is not good. And if you require an app, or even worse an active data connection, well, I much prefer a quick double-click of my phone’s side button and then putting it near the payment terminal. And I’m really skeptical about security. NFC is vulnerable to relay attacks and QR codes can be secured by using one-time codes or roll…
And there was always the fear that your phone dies and you can't take the subway or purchase everything. It doesn't happen often but on some long days you really don't really want to be tracking the battery of your phone super closely.
NFC payments can work offline (although this is pretty rare) and can be authorized from a small plastic card that has no battery, no internet connection and is pretty robust including being completely waterproof. Plus 100% of the time I tap my card or phone on the merchant's terminal. No alternate UX option. Plus if you are using your phone for payments (which is a very convenient option) you don't need to open any app beforehand (WeChat is like 3 taps to get to scanner or code) and I found quick NFC reading to be more reliable than scanning a QR code where the lighting conditions and state of the QR code are not always perfect (it was almost always possible to get it to work within a handful of seconds, but often took a bit of fiddling around. NFC is reliably just tap and it works).
I still keep a few large bills in my wallet in case the card networks are down, flag my transactions or whatever else. But having this immutable payment card that is incredibly reliable and easy to use is way better than the phone-based QR systems I have seen.
What I would love to see if we bring phones into the system is a way of approving the transaction (including the amount) on your device. So for example 1. Tap phone 2. Review amount on screen and approve 3. Tap to commit payment. This is more steps but is far safer. That being said the number of times this has been an issue for me is 0, so it is probably better to just rely on the banking system to correct any mistakes rather than add extra steps to the payment flow.