If you're talking about physical gold, the 'privacy' does not derive from the gold itself. It is not 'private' in any sense.

The records of ownership on the other hand are private. It may be "kept" private by hiding it in a vault, but the privacy is not a property of the monetary media.

There is a lot of confusion between 2 things: Privacy and Anonymity.

Cash is anonymous but it is not private. If someone sees a $1000 note lying on the ground, the lack of 'privacy' of that $1000 monetary media is not going to detract from its attractiveness. It might have had an owner, but the owner's name is not 'stamped' on the note (hence it IS anonymous).

On the other hand, credit money - which is a record keeping exercise - involves records which are kept out of the public view. They are therefore private but not anonymous. They are private (as distinct from 'anonymous') for 2 reasons:

[1] - it is 'backed' money and not base money, which means its only any use if a trusted party is prepared to exchange the numbers in my account ultimately for cash. This leads to the need for a counterparty in the 'trust' relationship and therefore point 2...

[2] - accounts are synonymous with persons, since they (unlike cash) have no value on their own. The credit or debit balance is only meaningful when associated with a legal entity who inherits the obligations represented in the account records

Since cryptocurrency is void of a trusted party (backer), it therefore has to adopt the cash model - not the credit model. We cannot think of blockchain addresses as 'accounts', they must be thought of as being independent of people - like gold nuggets. As such one cannot build a privacy model around obscurity, hence the need for a public fungible blockchain so that there's no conflict between transparency and anonymity.