1. Yeah, I agree. I just think you have to be careful about implying that a cashless society means the absence of any kind of physical currency (rather than just the absence of gov't-backed currency) 2. See 1, and I'm fine with the expression "cash prohibition" as a tool for persuasion as long as you're clear about this being prohibition of gov't-backed physical currency. 3. I'm still not convinced - as you mentioned in the OP, the gov't already charges a sort of "rent" for using currency, i.e. taxes. As such, the shift away from cash wouldn't mean rent where there was none, only a shift in who's collecting the rent. (And re: their contribution not being 'worth it', arguably because there are a number of such providers in competition with each other and the price is what it is, the price is at equilibrium, or close to it, implying that a sizable percentage of consumers do think the rent is worth it.)