Yes, but back then all air travel was the equivalent of first class, today - including the prices. When price points dropped enough to allow the Greyhound Bus hordes to take wing, they brought their wardrobe traditions with them. :)
You’d have to be crazy to dress to the 9’s now.
Cramped seating, bumping into people, bags, toilets nearly too small for normal humans. Why wear your best, to ruin it? To be utterly uncomfortable while sitting on the tarmac sweltering in the sun because the airline wants to save fuel by not idling the engines, instead running the miserable overworked APU?
Or due to overly safety conscious pilots leaving the seatbelt light on the entire damned flight? Heck, you may wet your pants, hope they aren’t expensive! Next time, I will wear a damned diaper in case the pilot decides we do not need the toilet for 4 hours!
I will start dressing when I own my own G6.