isn't this what FIAT actually does ?

you don't turn something into nothing, it is only a matter of exchange-platform , when you sell your house for fiat you know that fiat itself can't give you shelter, but it's simply an easy unit of exchanging your house for 2 cars and a small studio,bitcoin isn't any difference from that aspect. after all , all these payment methods are nothing but a medium of exchanging ownership of "actual" real life items.