Lungs are not muscles, they are organs. Lungs can’t do anything by themselves, they rely on surrounding structures to do that. Lungs can’t be made bigger by exercising (that’s like saying you can make your liver stronger by drinking…ok that’s maybe not a great choice of metaphor due to the negative relationship between the liver and drinking!)
Lungs expand to fill every nook and cranny of the pleural cavity as it expands. In fact, the more the cavity expands the more air can fill the lungs. Consequently, if you want to take a big breath, you must move your ribs.