SWA is over 40 years old, is highly unionized and is more akin to a legacy carrier than an LCC with regard to labor costs.
You might care to add "Consistently profitable" to that.
Regulation was a protection racket for the lucky few customers and employees that were involved.
Where as Chapter 11 Bankrupcy protection is a protection racket which kept unprofitable carriers in business and artificially lowerd pay and conditions fopr employees throughout the industry in North america.