The bitcoin in my mind is no less imaginary than the 10 commandments, which are written in so many copies around the world that they can’t just be forgotten (they’re really even more secure, because you can’t change a single UTXO without rewriting the entire chain thereafter… virtually impossible)
Also your gold is just a shiny rock unless you can find someone to trade you something for it. Desert island gold is no more useful than desert island Bitcoin.