When the telcos tried to compete with the cloud providers by offering OpenStack they learned the business wasn't as simple as offering 10-15 services with some racks. I can imagine the same hidden complexity for payment rails
On the other hand regulations have taken too much power away from merchants and Wero could succeed with more merchant friendly terms. They are doing 3-legged payments so they are not subject to as many European regulations as Visa/Mastercard.