What you describe is exactly how Visa, Mastercard, AMEX and the like operate... literally taking money for doing nothing beyond being a middle man. Yep, they take a cut of every transaction that goes over their networks and they've been working diligently to make sure every single transaction goes over their network.
[Emphasis mine]
You are not telling the whole story here.
I'm currently in the middle of a $15,000 purchase dispute with a Chinese vendor (for a CNC system). The device arrived non-functional, the merchant's customer service is wildly non-useful and time consuming, and after 3 months of dikking around I've decided to send it back.
I have clear E-mail evidence from the merchant acknowledging the problem, the CC company yanked back the payment and is forcing the merchant to issue an RMA for the device.
The credit card company isn't on my side, nor are they on the side of the merchant - they are on the side of honest transactions, and they police those transactions for me.
Twice I've had my CC info stolen at a restaurant(*), the CC company detected fradulent purchases, and issued me a new card. A couple of times they incorrectly detected fraud, and a quick phone call sorted that out.
All of this is value added to using a credit card.
It's not *just* rent seeking on transactions, it's also providing a service: "peace of mind" in your purchases.
If anyone is interested, ask ChatGPT about the Fair Credit Reporting Act as regards to dispute resolution. If you receive a defective product, you have 60 days from the statement (not the purchase, but the statement) to initiate a dispute, and there are several "states" the dispute can be in, such as "vendor is working with the customer to resolve the issue".
It's not just rent seeking, the extra 5% CC fee for the purchase is for "peace of mind".
(*) Don't let the CC out of your sight. If the waitress takes the CC away from your table, she can easily write down the number and security code before bringing it back.