One smaller use case that comes to mind is for immigrants like myself. On an H1 visa, you are only allowed to receive a paycheck from the sponsoring employer, so you cannot do contract work for cash (stock is ok), but paying down debt might be a cool way to accept "payment" for services.
That's a very interesting use case. We'll have to explore more the limitations of H1 payments, but this could be a way to receive "payment" by directing it to your bills / debts.