A fixed exchange rate might be realistic and workable if the world's economy was fixed and never changed but under capitalism it is dynamic, unpredictable and subject to weather, natural catastrophes and governmental idiocy on a massive scale. There is no way a political decision on exchange rates could hold up over the long term much less the short. Who would you trust more to arrive at a correct rate or system of rates? The international monetary markets or some government bureaucrats?
All they have to do is define an atomic standard. IE, 85 moles of C-12.
The gold standard was a very popular, political value. And it prevailed for almost a hundred years of the most fantastic economic growth in the history of the world.
Why? Because it was decided and controlled by the people. It was a popular decision.
This of course, like elections, was annoying to elites.
You can not say, that the Fed is a champion of dollar value? We’ve lost 99 percent of what stayed steady for a hundred years. If anything the Fed’s standard is constant anti-standard.
In short, money is too important to be in government hands.