We only need fiat cos it’s what most people believe in. Hoping one day tho in the next few years we will be able to use both. Beliefs are changing but i doubt that will extend as far as companies like visa because blockchain supercedes it. The only advantage being that visa insure themselves and can quite easily afford to pay people off when something goes wrong.

Until there is something similar with crypto to help establish a fairer trust relationship visa will always be ahead