With Wero it's across all banks, building on the recent instant transfer that is being rolled out quickly while still having the same, familiar UX as PayPal or other apps like that while being a EU solution.
If you look at the video for how Wero online payments work (https://www.youtube.com/watch?v=Bu5_X3oSgHM), you'll see that an EPC QR code could just as well be used (with a banking app installed instead of Wero).
With Wero you probably also get automatic processing of the incoming payment, without having to connect the financial transaction to a purchase yourself. But payment through bank transfers is also available through the payment service providers and costs less than Wero (at least it costs less when using Mollie; the Stripe fee is the same for Wero and bank transfer, and Adyen apparently hasn't published the Wero fee yet). So you'd still get the same service for less money.