Asset backed currencies have been the ONLY succesful models tried. They stood for centuries, none ever "failed" they were all replaced by fiat systems.
Fiat moneys have ALWAYS failed. The ability to "print your way out of trouble" is in fact "printing your way into trouble" and will always end bad for the users (good for the bankers).
It's not that simple and straightforward. Actually there's not much difference between "asset backed currencies" and "fiat moneys" in respect to what makes them all money