You'll never get a negative interest rate with cash. When cash is completely eliminated, you will be at the mercy of either the bank(s) or the central government in the case of CBDCs. When the government wants to increase the velocity of money, they'll force interest rates to be negative, which will strongly influence you to spend your money rather than save, for if you don't spend your money, it will gradually dwindle to nothingness. I'd rather have cash, or better yet, something with true intrinsic value, be it gold, silver, or some other tangible good with a long shelf life which is suitable for barter. Throughout history, people have used many things as money, such as animal pelts and tobacco, to cite a couple of examples.