Everything you are saying is true but still does not reflect the fact that I can purchase an item with a credit card and at the end of the month it is cheaper than if I paid cash.Let me put it this way. Credit card companies are in the business of loaning money then making money off the money they loaned. They are charging you interest on that money, along with fees to use their card for you have access their money.
How long would anyone stay in business, if they were just breaking even or losing money? Without profits, no business stays in business very long.
I don't dispute that you get the $50 to $75 back at the end of the month. But I'm pretty sure they made a lot more than that off the sale of he items that you bought. Maybe not directly from you, but in the bigger picture, the seller paid a transaction fee when he allowed you to access his credit card machine.
I know this to be a fact because my brother utilizes a credit card machine for his business. It costs him 1.2% for every transaction he does with credit cards. So he charges more for credit card sales than cash sales. Now for him, this is about convenience because a LOT of people use credit cards, and many of his corporate accounts use credit cards for their maintenance and repair shops for keeping track of their expenses. Also, credit card sales are deposited directly into his business accounts. Many of the companies he deals with have moved away from using purchase order numbers for billing and have gone to using credit cards instead.
I find that virtually nobody that I deal with gives a cash discount and almost nobody charges a surcharge fee for using a credit card short of government agencies and a short list of businesses. At the end of the month for me it adds up to money I saved which I usually apply to my credit card bill. My best example is still paying for postage at the post office. Pay cash or pay credit card and total bill is less because of cashback. I have not seen a discount at the post office for cash.
In my case with some quite hefty medical expenses all paid with credit card it adds up to some significant dollars and provides a great paper trail for the IRS.
I rarely have to drive to the bank to cash a check to get cash. I deposit checks directly to my bank either by ACH or using my iPhone apps and it's camera. Some things are obviously paid in cash. They are becoming few and far between.