I don't think bitcoin will die. If you observe it everyday, it is gaining more investors and user base. More country is getting open in accepting bitcoin transactions, and more project and development is observed. Even if bitcoin power decrease due to a more popular altcoin in the future, it will stay alive because of the baser user it established.
Same what i was thinking bitcoin will never die, until more people using bitcoin this will exist and continuous adoption by more people it will get stronger and increase the potential that bitcoin life will go long lasting.
even now I think users could die first, rather than bitcoin. so I do not think bitcoin will die. but I myself will leave bitcoin because of age who are old enough will definitely not be using bitcoin again.
bitcoin will continue to grow in the future I'm sure, so it will not be easy to die, but in the future will be more widely and used by many people.