If bitcoin die I dont think altcoins die. Yes some altcoins for sure die because it deoends ti the bitcoin price but they have altcoins deoends to the dollars price and for sure it will still a live what ever happens in bitcoin. But as of now bitcoin will not die and it will live in the online world in the next few years and bitcoin will become more powerful and popular so the price will continue to increase.
but i do not think that bitcoin will ever die. i am sure that bitcoin will remain as for ever, and all the other altcoin will work with the coordination of bitcoin. although altcoins have no concern with bitcoin but still people use altcoin for investment and trading while bitcoin is the basic currency where people put their assets as safe and the main place to use it form here for different purposes.