If Dollar dies, everything dies. Simple as that.
Simple Logic: If bitcoin was better than Dollars, why does everyone freak out when we see a crash? If bitcoin was that good, you wouldn't give a fuck about the price drops right?
So you mean if dollar dies every other thing will die, right ? What about other currency in the world or does it mean that everyone is using only dollars or must use dollar only ? Let assure you that even if dollar dies, things will still be moving fine except that for short period of time some negative impact may be felt.