Whilst true, there are distinct
classes and
types of assets, with differing characteristics.
Currency is exceptionally liquid (interchangeable) and nearly-universally accepted within a particular region.
Stocks, bonds, and other financialised instruments tend to be better inflation hedges, as currency will, does, and should inflate and deflate to meet actual transaction needs, and to dilute excessively burdensome debts.
Real estate is exceptionally durable, tends to hold value well (excepting speculative bubbles), and serves excellently as collateral for debt. Other long-term tangible property (e.g., industrial plant and equipment) can play a similar role.
Commodities tend to be intermediate between cash and other forms of financialised instruments, generally having inherent liquidity (that is, the commodity can be sold for use-value), as well as its investment role.
Collectables ranging from fine arts to wines to luxury automobiles tend to have hold value well (again, modulo speculative bubbles), and are both more readily stored and transported than real estate.
Cryptocurrencies tend to most strongly resemble the latter, in both their intrinsic durability (which is NOT the same as price stability), and their portability, which is to say that they serve as a highly effective way of moving financial wealth between jurisdictions, often without any external visibility, though of course blockchain transactions, like diamonds, are forever.