What is necessary is that it is widely saved, so that prices are legible between us and we actually accept the same form of savings. The categories you listed other than gold have counter-party risk. This is an indication that they are not final payment and thus investment rather than savings.

Satoshi owes you some Bitcoin for maintaining his ledger. He will never, ever pay up. A pretty silly investment but it did have a lot of libertarian technerd hype around it.