There's a reason why several of these gold backed cryptos have already popped up and pretty much has done nothing major.
I think that the primary reason is that the value of a gold backed crypto comes solely from the fact that you trust the custodian of your metals to keep it safe and not just run with it. You also trust them to run a full reserve instead of a fractional reserve. By having a gold backed crypto you're also handing over control over the entire money supply to the founder of the blockchain, as he is able to constantly add new units to circulation.
Essentially, this is going to be no different to centralised stablecoins like Tether, except with gold. I don't see how this not so trustless system is any better than bitcoin itself.
It may not sound like a more trustable system than what we've already got with bitcoin, but that's not going to stop a major financial power from trying to implement it. The Chinese have been buying up assets from Vancouver to Cape Town in an effort to show their "soft power" or financial dominance around the world. This Yuan-sponsored-gold-backed-crypto would be more of an excuse by them to step in and try to replace Bitcoin. Not that it would be a good idea for us.
And regarding the debt, another thing that is often missed is the GDP figures. 18.57 trillion GDP is not that far off from 20 trillion in debt.