Not saying this is the case here, but the answer is by bankruptcy and continual capital investments. Let's assume that some small number of airlines continuall

Not saying this is the case here, but the answer is by bankruptcy and continual capital investments. Let's assume that some small number of airlines continually make small profits (or at least break even). That creates a non-negative balance. However, let's assume that a number of other airlines are frequently being established and receiving capital investment, before ultimately failing and declaring bankruptcy. If the losses those airlines represent outweigh the positive balance from our successes, then the industry loses money, despite some players continuing to exist. To take it further: if you assume people keep making capital investments with capital drawn from other industries, it's possible that the industry continues to exist even whilst no company generates profits in the long term.