Networks like visa and Mastercard don’t seem evil. If you’ve ever had to dispute a charge and got your money back easily or relied on the fact that even if their computers are down they’ll still take the risk and allow you to take money out of your account you’d find the fees they charge pretty minimal. Now the issuer bank… that’s where most of the fee and why most banks now have reward cards because the issuing bank can ask for whatever additional fees on top of what visa/mastercard does.