Agree that Bitcoin gets maintained by Core Developers, but why do you think that it might "die"?
Bitcoin is an open-source project and all the material related to it is available on github for developers to be able to do anything with its properties.
Don't you think these Bitcoin Cash and Bitcoin Gold coins must have that open-source code used in it to be called "Bitcoin" before their alternative names?
Even if they stop maintaining the system, the base is too much firm that contains many more reputed developers who would take over the project to continue developing it in the future and add upgrades eventually. Don't be too scared, when a "bulb" was invented, did it stop there only? We now have LED lights available for some great brightness at less expenditure (electricity consumption).