Southwest doesn't do this, but some other low-cost carriers do (especially in Asia): they purposefully cancel flights and offer only credit vouchers as compensa

Southwest doesn't do this, but some other low-cost carriers do (especially in Asia): they purposefully cancel flights and offer only credit vouchers as compensation instead of re-routing passengers. Many travelers end up buying same-day tickets at considerably higher expense, or not ending up in a position to use those vouchers (which is the same as the airline keeping the money).