They reflect different threat models. If you believe that governments will get swept away by the global market-state, Bitcoin is your asset. If you believe that society will crumble and we'll be back to trading with other villages, gold is your asset.
But why would a modern apocalypse look identical to the 1600's? I think some tidbits of technologies we've gained since then would be scrapped together by industrious survivors.
What was used for "currency" in prior dark ages before the 1600's? I'm guessing it didn't pan out well for the guy who stockpiled cowrie shells in between.
Populations tend to the hardest money. Bitcoin cannot be undiscovered.
But you're right that Bitcoin cannot be undiscovered. It wouldn't surprise me if the dominant currency would be some other cryptocurrency with built-in inflation (maybe ETH, maybe XLM) that remained outside of the ability of some single entity to cause runaway inflation.
Elsewhere in the thread a lot of people say that gold has real tangible value. Sort of. It's tangible in that you can hold it in your hand and have physical possession of it. But "value" is always in the eye of the beholder - currencies are valuable if other people think they are valuable. With today's world, there's no guarantee that'd be gold - it could be silver, or cowrie shells, or bullets, or cigarettes, or Juul pods, or USB sticks, or n95 masks.