Okay - I will bite. How did they fail?

Gold has worked - nearly flawlessly. In the 1800s it gave us all we have today. Transportation, communications, automobiles, coal/oil/gas. All these technologies were from hard money times - we just built upon them.

Even before paper, Governments would clip coins. That's how profitable it is for Government to cheat the people!

My point is no real money (based on real energy and scarcity) failed without first being debased.

Can you give an example otherwise or recommend a book?

Principles of Econoomics by  @saifedean covers this too.