Has the typical cabin pressure in airliners changed in recent decades?
Let's take the Boeing 737 as an example: an airliner that first flew in 1967 and is still being produced, its variants—old to new—indeed show a trend of increasing pressurization capability.

Note that even the 1967 variant had an automatic controller for the cabin pressurization, and the 200Adv and the Classic shared the same max ceiling of FL370.

The better the engines and the aerodynamics are, the higher they'll fly, and the stronger the aircraft will be made to offer better cabin altitude. However stronger is now easier than in the past thanks to the materials engineering advancements.


  1/200 (7.5 psi) → 200Adv (7.8 psi) → Classic (8.65 psi) → NG (9.1 psi)


The higher those values, the lower (denser) the cabin altitude is, for a plane flying at the same altitude.

Those values are the limits, each variant will use lower values in the day-to-day operations to reduce the stresses.



Source of the figures: b737.org.uk