Well, currency is based on consensus, certainly, but that is not enough to create value. A paper has not value intrinsically speaking. Gold and other metals have always had value for various reasons (either because of their physical/chemical properties or because of their rarity). So, the day the Dollar loses its consensus, you are left with worthless paper and you might as well use them in the toilet. The day Gold, Silver and other lose all actual value is not in sight. Net, you are safer saving some of your assets in those.