We still use fiat and paper money because the government gives value to that paper. What exactly makes the paper worth?
whereas many other goods have value and are worthed to be used and have a stable value such as gold?
Our own use gives them value. It's the idea behind it. Not just the 'mighty evil - government'.
And to all honesty, I think, if you and me, would sit at the beginning of the new world, I am sure we would look into a way to exchange value.
And even with the best intentions in our mind and heart, we would develop a form of currency.
The problem is not the idea, but how does it enable humans to do harm and good.
Even crypto nowadays has many of its own problems. Even for some criminals it is easier to use crypto.
So, like money, a currency will always have a double edge as long as human beings will have double edge (call it good and bad).