Gold has use value. It is and has been traded for its use value, which is the same value whether or not it is designated as currency.

The decision to designate gold as currency, or a standard for currency, is political.

Thus, gold is natural, and naturally useful, and may be designated as currency politically.

Cryptocurrency has no natural or intrinsic value, no use value.

Unlike the trade of gold, the trade of cryptocurrency depends on a belief that it is currency. Yet, it is not currency, because it has not been designated as currency politically. Once the realization is made that the necessary political process to designate it as currency will never occur, the will to trade is lost.