A monopoly was developed because it's easier, and I'm sure that's why there isn't anywhere in the developed world that successfully made use of multiple currenc

A monopoly was developed because it's easier, and I'm sure that's why there isn't anywhere in the developed world that successfully made use of multiple currencies, or private printing of the dominant currency. For example, the American colonies operated without standards for the first few decades and it was a huge pain in the ass for everyone: https://en.wikipedia.org/wiki/Early_American_currency https://en.wikipedia.org/wiki/Early_American_currency