I don't think crypto like Bitcoin should only be viewed as a do or die replacement for fiat. It can easily complement fiat by allowing cross-border transactions of value, microtransactions, being used as a method for privately transfer value and so on. Government coin won't be a competitor to any of it, because it would be a very centralized system, like PayPal or Venmo but owned by state - it just won't have the same properties as true crypto.