Bitcoin is a fault tolerant distributed network. There are thousands of nodes around the world. They can join and leave the network at will. It would take a world wide cataclysmic event to bring down every one of these nodes in a way that they cannot be brought back online. My guess is we'll have bigger problems to worry about if that happens.

Here's a game to visualize the concept. https://bitcoin-battleship.vercel.app/ h/t @jasonb