Airlines basically were a regulated utility until they were unregulated to the point where normal people can barely fit in a seat and there’s basically no amenities anymore. It used to be kind of nice to fly. That’s laughable now.
On the other side of that coin, when airlines were heavily regulated, most people couldn't afford to fly at all.
The "regulation vs. no regulation" stance is the wrong way to look at it. Airlines are still regulated, of course. Maybe some of the regulations we do have are unnecessary, some of the regulations we got rid of we should really bring back, and perhaps there are others that we never had that we need.
What other things changed besides regulation?
My guess is MANY more people fly and are able to afford to fly vs before. There are probably many others things that changed.
It's also very nice to fly.... in first class.
Now you have to option to pay as much as you used to (inflation adjusted) for a ticket, and get first class service with all the leg room you want.