you shouldn't even be comparing bitcoin and gold because they have nothing in common and not in the same category for one to replace the other. bitcoin is a currency and gold is many things but not a currency.
They have more in common than meets the eye. Both gold and bitcoins are
commodities as conventionally defined. More specifically, they could also both be considered
commodity money -- as opposed to fiat money. After all, gold-money has served the function of currency for thousands of years. Bitcoin as a currency is actually much more immature.
Gold has other uses of course, although "money" (store-of-value, medium-of-exchange) is obviously the primary one. The OP is specifically talking about the store-of-value use case.