In crisis I would rather have the food, water, and ammunition. What a silly strawman. A warehouse full of survival supplies is incredibly valuable during crisis but it is not durable and must be maintained when not in crisis. For the long term representation of wealth I would rather have a vault of gold just like every nation on the planet. Nearly everything else degrades in a fraction of a lifetime. Gold will be exactly the same after sitting untouched for millennia. For the long life of nations this is extremely important. For the comparatively short life of a human this is less important but still valuable.
A casino is the best analog that I can thing of at the moment. When you want to play in the economy of a casino you are required to change your dollars for chips. You have to trust that the casino is not going to steal your dollars and will actually give them back. They practice full reserve banking where every dollar represented by chips is in their vault. The same is true for a gold standard economy as practiced sans full reserve. Gold is the money, banks do the job of verifying gold and exchanging for easily carried and traded tokens, dollars. You have to trust that banks or governments aren't going to steal your gold. If you don't trust them you change your dollars back to gold. If a lot of people lose trust you get bank runs. With fractional reserve banking there isn't enough gold to pay back every dollar and you get crisis and bank failures.
With any currency its value comes down to trust. A gold standard allowed people a way to keep their wealth in a durable form in times of low trust with no conversion cost. It allowed people to "take their ball and go home" so to speak. No governments needed to trust another country's fiat. The money exchanged in trade had a real, verifiable, persistent value.
Yes, a gold standard has some problems. Barring straight barter with physical gold it is still the fairest most robust currency system humans have come up with. Whatever excuses the US Government gave for ending the gold standard it still acted unconstitutionally. The government was facing a damaged economy and dwindling gold reserves as people and countries redeemed dollars for gold. The government saw their dwindling gold reserves as a problem instead of a function of a gold standard. This is the same as a casino seeing a lot of people cashing chips in and seeing their dwindling cash supply as a problem. In both cases it is a loss of trust in the token issuer that caused their supply to dwindle. It wasn't a problem with the currency it was a lack of trust in the issuer that the issuer saw as a reduction in "their" money that needed to be stopped. It was never "their" money to start with. It always belonged to the people. The people were just taking their ball home.