I guess this is the time to dive into the parallel universe, ey?
I don't really think that Bitcoin will really disappear through means of not being functional as a coin, nor having 0$ in value. That's really far from it to happen and it is almost impossible to happen, but hey anything could happen in any second, right?

If there's gonna be End Game chapter for Bitcoin, I believe it is gonna be the one that is entirely manipulated by the government. You can still feel the same things that Bitcoin offers, but it is indeed renamed by the governments.

Almost many country already planned to make its own crypto coins, so I don't think they'll be able to do this.