But there's a giant problem. Gold is a worse money substitute than fiat. Even if you have willing buyers and sellers, gold suffers from lack of liquidity because of the need for physical transport.

Silver filled that need for liquidity when societies used bi-metallic money systems. Gold for the large purchases, silver for daily use.

As for crypto over gold, I don't see it that way. It's more like crypto and gold. Crypto is only as good as the electronic systems in place. Once those fail, it's worse than useless. At least fiat can be used to light the fireplace or a trip to the loo. Then it's gold (and silver) to the rescue.

If anything, gold is the BREAK GLASS IN CASE OF EMERGENCY money. We can use crypto as much as possible, but when it becomes impossible we can still use gold (and silver).