It is said that bitcoin will destroy the fiat system but i believe that if this happens the world will change completly because banks and a lot of things will go out of market.
As we can see bitcoin fastly known by everyone.Bitcoin users will grow but then, we cant expect everyone to fully trust it.Some of them will still have doubts and threats.But once bitcoin proves itself to everyone, then this doubts will be removed and everyone will be expected to use it.