Gold for bread only works if there is still some semblance of law and order, like in the video.
And it (or better yet, silver: more easily divisible) is good to have some metals for such situations.
But in the case of WROL (Without Rule Of Law), the man without lead is dead (and people with the commodities you want to barter for will not be interested or n gold/metals. They will want food, ammunition, gasoline, alcohol, and other practical necessities.
Then later, as societies begin reforming, metals will regain value as stores of wealth. But in a total SHTF scenario, they will be worthless.