Money has value insofar as governments use it to collect tax - so long as there’s a tax obligation, there’s a mandated demand for that currency and it has some value. Between different currencies, the value is determined based upon the demand for that currency, which is essentially tied to how much business is done in that currency (eg if a country sells goods in its own currency, demand for that currency goes up and so does it’s value).

This is not the same for crypto, there are no governments collecting tax with it so it does not have induced demand. The value of crypto is 100% speculative, which is fine for something that is used as currency, but imo a terrible vehicle for investment.