Value is based on scarcity, and since no one is likely to be using actual physical currency in 1000 years, a hoard of US coins and/or paper money will be valuable as collectibles.
Gold and silver are bound to be found in and processed out of asteroids in vast amounts. All the gold ever mined on Earth would make a 80-90 foot cube, scarce, hence, value. It’s a commodity, nothing more.
Value is based on scarcity, and since no one is likely to be using actual physical currency in 1000 year
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That wasn’t true for the last 5,000 years. Those that forget history……