You're still paying for credit card transaction fees indirectly when you use cash. Since retailers are prohibited from charging discounts for cash purchases then to cover the card fees they raise the price for everyone. Cash buyers end up subsidizing card users.
The fees aren't the point. The point is, using something other than cash tends to trick people into spending more in the same way buy one get one free does.
People being unable to control their impulse to buy something they can't afford is hardly a trick. I would maybe say that a casino that utilizes visuals and sounds and other mental techniques might be "tricking" people, but I can't say the same for credit cards.
All the information is there, in plain english, to allow people to use a credit card simply as a way to keep an electronic ledger, get an interest free loan until the auto pay date, earn some cash back, and have some purchase protection via the ability to do a chargeback. You can even set spending limits online.
Similary, I wouldn't say a buy one get one free offer or 75% off sale sign is tricking anyone either. Assuming you've passed 4th grade, you're stupid if you're not calculating unit prices.
