> Implementing all of these would require changing the constitution. A statement like this requires being explicit about the country or set of countries in que

> Implementing all of these would require changing the constitution. A statement like this requires being explicit about the country or set of countries in question, narrowing down the set of constitutions that would require amendments. If the legal system of a country does not explicitly require merchants to accept cash (some places do, some don't - just like in some places a merchant may refuse a customer and in some they can't), it is technically possible to create a practically cashless environment without having to explicitly lock anything down explicitly, but merely by creating an incentive to not accept cash. There's barely any practical difference between no one (save a few die-hards acting on a principle) accepting cash because it's inconvenient to deal with (or simply unfashionable, hah) and actually blocking cash acceptance - the model is indeed different but outcome is ultimately the same. For an imaginary extremely powerful and nefarious adversary the former model is even preferential, as it provides a plausible deniability. Whenever there's such and adversary with a will and power to do so is a separate question which I'll intentionally avoid.