to correct you:
its not MONEY
but is a currency
there is a difference
no government can decide what currency is. cigarettes in prison can be a currency, sexual favours/beer/cigars/pizza between friends in exchange for other favours can be a currency
governments can only decide what is or isnt MONEY
currency is a umbrella term which pretty much anything, which everything then fits into sub categories below the umbrella term. for instance
assets are investment holdings currency(gold, art.antiques,bitcoin)
commodity currencies are raw produce used to make secondary products (beef, wheat, gold, oil)
mortgage/credit agreements/insurance policies(the contracts/promissory notes themselves) are a currency but not money they are asset currencies (banks privately trade these behind the scenes)
money is legal tender of a country and authorised by law of the nominated/named country to be used to buy things and by law pay taxes/court fines/pay minimum wage
in short
crypto assets are a currency but are not money
I'd say the definition they defined at the G20 was pretty accurate. Most cryptocurrencies at this stage are not currency they are assets, they are largely being bought to have access to certain services or uses and for investment.