Nothing in this world is permanent, and that's going to include Bitcoin. I'm sure it's going to take more than a dozen lifetimes for something so great to be invented that could potentially replace Bitcoin though.
That is one question that everybody in cryptocurrency might ask and that is the question whether Bitcoin will disappear or not. That of course will depend on many factors. I don't even think that it will disappear. There might be a possibility that it will be replaced by some other cryptocurrency that will dominate the markets. Ethereum is a big contender in the quest for dominance and many are already speculating that it might not be long for Ethereum to become dominant.