Bitcoin can not just die in a moment. Even if miners cease to serve the network, new ones will appear. The concept of decentralization does not die as bitcoin is not the only currency on blockchain
The OP gave us an scenario but it is very difficult to picture an scenario in which bitcoin just dies after all why the miners are going to stop mining bitcoin, their mining hardware is only useful for one thing and that is mining and if they stopped mining bitcoin then they will lose money as a result of their actions and they are not in this market to lose money.