I think it really can not die but adopt, or be adopted, by some kind of innovative tech and transform following the rest of the world. Yet for now it's really the other way around. 
I think you are maybe right about what you say. Bitcoin can live long life, or maybe it will be adopted as you said in near future. But i think that, adopting could happen to many other fiat currency, because i believe that in future near of far who knows, people will have one ultimate currency that they will use. It will be some kind of cryptocurrency, and all people on earth will use it.