What's your point?
Did airlines get cheaper due to deregulation or because technology and engineering made operating them cheaper?
Case in point: Old Perry Mason shows where characters regularly drive to the airport, pay for a ticket and get on a plane. Flying was actually faster than driving back then, even when measured by time between deciding to leave and arriving at destination!
(Yes, tickets used to cost a bit more. Whatever. Figure in the price for camping in the airport for 4-5 hours, and then tell me the current system is cheaper!)
Tickets used to cost 4-8x what they cost now, depending on route. It wasn't a couple percent extra. A lot of what made flying seem like such a glamorous activity was that everyone but the upper classes was excluded.
An economy class round trip from the US to Japan in the 1970s with Pan-Am was $8,900 in 2026 dollars. About $15,000 if you flew first class.
Deregulation also allowed international carriers to sell to us too. An ANA round-trip on economy class is a couple hundred dollars cheaper. Their business class is similarly cheaper than Delta One.
Air travel is so much cheaper than it was back then that it is affordable for most people to take one international trip a year if they really want to. Even to exotic places in Asia or Southern Europe.