Yes, Nick! Right on. I like your thinking. I have a similar approach. I have only two credit cards, and they are both cash back. I use one primarily, the second is only for backup when needed.
The banks know, however, that there a people like us around. They lure the unsuspecting into another kind of trap. That trap is overspending. The banks charge the merchants for the use of thier card, so more sales equals more money for the bank, although the money does not come from us it comes from the merchant. We just have to be careful that we buy only stuff that we would ordinarily purchase, or we spend extra money anyway and end up losing. So if you are careful, it can work in our favor.
THe banks work on the law of averages. For every person like you and me using a cash back card, there are probably 10 overspenders.
THe banks have studied spending habits and it is conclusive that if a credit card is used, most, or almost everyone, will overspend.
I write about that here.
Can I quote you with your "method"? I can make a good post about your idea. I will put a link to your medium page to perhaps increase your traffic.
Keep up the good work!
Max