If and when cryptocurrency finally becomes an official global currency, how do you think it will affect the global economy and the economy of each countries? Will it help improve the economy better than fiat or will it still need help from fiat?
what do you mean by official global currency? What do you mean as a payment currency?
it is impossible, but if indeed bitcin is accepted globally by the whole world, of course there will be taxes on bitcoin, and obviously taxes from bitcoin can help a country's income, and that will help a country's economy a little.