I want to continue being able to pay by Cash as it's the only to guarantee my privacy. But, because of the miles I get using my credit card, I end up almost nev

I want to continue being able to pay by Cash as it's the only to guarantee my privacy. But, because of the miles I get using my credit card, I end up almost never using any cash. I'll have to think about this, do I value the plane trips so much that I'm willing to compromise on my values regarding privacy? I'm also going to look into blockchain currencies like Bitcoin to see what potential currencies would guarantee my privacy.