I agree that Bitcoin won't die, but rather it will go the way of the IBM mainframe: still a big business, but not the "mainstream" thing like it was.
Bitcoin not the last word in digital currencies, it's just the beginning.
IBM is a bad example for this. They used to be innovators but then they became satisfied with what they already had, which resulted in competitors overtaking them in new advancements and technologies, and now they play catch-ups
Bitcoin was never an innovation platform, in fact devs doesn't really pay attention to what other chains are doing.