I’ll probably get mocked again, but here’s another thing I didn’t know about regulation in the good ‘ol days of the 1970s (from this paper):
With capacity and route expansion foreclosed as outlets for product differentiation, the trunk carriers devised new means of service competition. “Capacity wars” gave way to “lounge wars.” On wide-bodied aircraft, lounges were introduced in first class, then in coach. When American installed piano bars, TWA countered with electronic draw-poker machines. Live entertainment proliferated, with musicians, magicians, wine-tasters, and Playboy bunnies.
When’s the last time you saw live entertainment on a commercial flight?