And paper money really exists as a physical thing and required technological and societal advancement to exist. Currency is an abstracting fiction to make trade easier. Confusingly they are separate in the same way money has no utility in itself but is portable and may easily be exchanged giving it high utility.

I think paper money is a novelty. It's a good invention. It detaches the concept of money from gold. It makes money easily transported. But that can run amok. The Gold Standard was in place to protect societies from detaching too far from physical reality. "Good" paper money should be backed by physical reality. The US has a large gold reserve, education, research, military etc. But we're now at the verge of running amok with paper money.