[floadaVonfoli]

the answer for this...

To go back to your original point, I don't see why a fiat currency issued by a government with a fixed value, even if backed by nothing, would not be acceptable in shariah. There could be reasons I don't know.

could be this...?

But yes, today's fiat currencies are all plagued by riba. This I believe is the fulfillment of the hadith in which the Prophet mentions that a time would come when no one would be able to escape being touched by riba.

the whole basis of the fiat currency is riba. without riba there would be no fiat currency. but not only that, but the whole system is tyrannical and oppressive. it is a zulm upon the people.