There are two separate questions under consideration here.
One is the capabilities of commercial general aviation air travel in terms of total elapsed travel time.
The second is the general commercial utilisation of air travel.
In the case of the first, advances in aircraft speed have been all but entirely offset by increased frictions in other parts of the air transport system. 2014 travel between NYC and Chicago is only barely faster than it was over 80 years ago. Moreover, aircraft speed is flat or declining since the late 1950s and the introduction of jet-powered aircraft.
The cost side is based on economics and other factors. In part, it is a question of both supply and demand. Costs have fallen through technological efficiencies; jet engines of today are roughly as efficient as propellor engines of the 1950s, not merely faster as was initially the case. They've also fallen through nonaeronotical advances: more efficient booking, higher seating utilisation, tighter seating spacing, and the like.
Statista's data extend only to 2007. Gordon gives data to the 1940s.
Among the big surprises to me a few years back was that peak avaiation fuel (at least through the mid-2010s) had occurred by 2000. Total passenger miles increased, but only through much higher load factors.
https://old.reddit.com/r/dredmorbius/comments/1wo2hl/boeings... (Search for "aviation fuel usage data".)
http://www.faa.gov/data_research/aviation/aerospace_forecast...
Gordon's data show inflation-adjusted passenger price per mile as essentially flat since 1990. Given miles travelled is a function of price per mile ... a similar relationship holds. Rise and Fall, p. 401.