whatever substitute one poses in replacement of currency or any other aspect, its bounded to get failed and its failure will be just a matter of time.
Its the same like emergence of communism when some people, like Hegel and Marx. lead the rest to run through current system. They did so as reaction to capitalism as they witnessed the exploitation of poor by the corporates and multinationals.
This feat currency system can not work because it has got inherent flaws in that. Islam makes it a condition for currency to have some intrinsic value and currency can not exist with out having some intrinsic value on its backing, which is not the case today. Secondly, that value is defined clearly in the text so there is no reason for us i.e. muslims to go for any other option.