Paper money can be counterfeited. Gold cannot be counterfeited, gold survives all rot, gold can be divided up in amazing small amounts.
No other metal — not platinum, not silver, not palladium, not black gold (rhodium), or any other metal can make those claims.
Gold is the perfect measure of economic currency, and value storage. It is not arbitrary to pick it for that highly valuable use. And history agrees, even if present spirit of the times does not.
Besides, we are off paper money now. It’s all electronic ledger entries.
It does not follow you into the kingdom of God, nor can anybody take it with them.