Governments can (and has!) "created arbitrarily without limit" metal currencies too. Given their monopoly on violence, they can just say "this coin now pays for ten pigs, not one, as you thought before". (Of course, they'd also decrease required tax payments correspondingly to maintain stable inflation.)

But haven't such debased currencies fallen out of favor, more often than not, in favor of those currencies that have not been debased, for example, the Florin https://en.wikipedia.org/wiki/Florin