alt Hacker NewsWero's Dutch predecessor, iDEAL, has been an established part of online payments for 20 years now.
As barely anyone has a credit card and very people want to deal with the faff of manually entering billing codes or account numbers, iDEAL usage is near universal for online payments. I don't recall fees ever going up as an end customer.
Card fees aren't paid by end customers either. The Swedish iDEAL equivalent, Swish, is more expensive than cards for smaller transactions (below 15 euros). Wero will be like Swish, not Pix.