This is great and definitely doable. It's the initial bit that's hard, people hate switching but then when they get used to it, they won't switch back.
What I'd really like to see is a pan-european payment processor, a European alternative to Visa/Mastercard.
A payment flow of 'scan code, confirm in banking app' is hard to beat and we're 95% there. And all you need is your own banking app, no shady payment processors required.
You lose some stuff like the credit part of the credit card (although virtually no one I know actually uses credit, only debit cards) and consumer protections (chargebacks), but I don't think those outweigh the extra costs at all.
The problem I've seen with this is that Wero works with banking applications that require either Google Play or App Store. Which means that you may not need an American company for the payment itself, but you now need an American company in the device you have to use for the payment.
What I'd really like to see is a pan-european payment processor, a European alternative to Visa/Mastercard.