Gold has been the standard currency since the beginning of time. Paper money and shares of stock would be rendered useless in times of war. In ELE or Extinction Level Events, even bitcoin would be useless. Have you seen Doomsday Preppers? Gold is the standard.
Gold can always enter the circulation market. Only when there is liquidity, the goods are truly valuable. And for the digital currency circle, security is very important, but at regular intervals, there will always be some related hacked news.