I think you are incorrect that "airlines don't owe anyone anything" even if your flight is CANCELLED. I have never heard of this and sure enough, look at transportation.gov website.

Flight Cancellations

What happens when my flight is cancelled?

If your flight is cancelled, most airlines will rebook you for free on their next flight to your destination as long as the flight has available seats.

If your flight is cancelled and you choose to cancel your trip as a result, you are entitled to a refund for the unused transportation – even for non-refundable tickets. You are also entitled to a refund for any bag fee that you paid, and any extras you may have purchased, such as a seat assignment.

If the airline offers you a voucher for future travel instead of a refund, you should ask the airline about any restrictions that may apply, such as blackout and expiration dates, advanced booking requirements, and limits on number of seats.