[throwaway-8c93]

Gold is a material with certain physical properties that cannot be replicated: it's attractively shiny, rare, dense, and chemically inert. These properties make it ideal for an international store of value across time. Moreover, those properties are independent of the current jurisdiction. Regardless of society's conventions, iron will never be worth more than gold.

Although Bitcoin's current implementation limits the supply to 21M BTC, the idea of a cryptocurrency can be replicated ad-nauseum and is 100% fungible. For all intents and purposes, it has no intrinsic advantage over, say Ethereum or Monero. The fact there are perfectly fine alternatives for it makes the value proposition much more shaky than gold. If people en masse, for any reason switch to other cryptocurrency, the existing tokens are rendered useless. And there are many scenarios in which this can happen - government action, protocol attack, untangling of distributed trust, breaking SHA256, BTC no longer fashionable, transaction cost creep,...