How can you charge lower card processing fees than Stripe or my bank?

“We operate our own payment gateway rather than reselling someone else's, so there is no middle-man markup stacked on top. You pay transparent interchange-plus: the wholesale cost set by Visa and Mastercard, plus one clearly stated margin — instead of a blended flat rate like Stripe's 1.5% + €0.25 that quietly bundles profit into every transaction.”