Regulated or not, the airline industry has many intense and relentless pressures always bearing down on it. Deregulation was a success by many calculations, including increased efficiency, lower prices, and increased service. The evolution of the airline industry is what some experts point to as the best proof of why deregulation, for all its troubles, ultimately is better than a regulated environment. While more regulation may have increased stability to an extent, the industry would have never grown as much as it did if the tight regulations of the past remained.
Back before 1978, the CAB had control (to a large extent) of the winners and the losers, as far as who could compete and how they competed. After deregulation, just as in any other free-market industry or company, winners and losers are based on the decisions they make and how they run their businesses. The airline industry and airlines figure themselves out based on what customers demand and what customers are willing to pay for. Despite the era of airline deregulation, the U.S. federal government still regulates safety and the air traffic control system, and steps in whenever either seems threatened.
Further Reading: Did ending regulation help fliers?