See:
There Is No Escaping History. Fiat Currency Eventually Fails.
Notice that this is a critique of fiat money -- not a critique of state-issued money under a gold/silver or other standard. Fiat money is a rare occurrence in modern history. (We live in strange times!) As we can see, the examples found by the author are a small number of short periods here and there.
I have my own critique of gold/silver standards, but that's another issue.
The problem is that now all the money issued by countries is fiat after the United States went out of the gold standard in 1971 which means that if the main fiat currency around the world the dollar were to collapse that could in theory collapse the entire economy of the world.
Yes im agree all money are related to dollar. Its very strange and i do believe every country need to use cryptocurrency so we would see how the economy condition more easier and more transparant by blockchain technology.