I once worked with someone who was perviously a consultant to a large airline and they dropped the size of their inflight magazine ~20 years ago to save weight and then were amongst the first airlines to drop it all together for the same reason

They figured out the $ they would save p.a with every change of page length, paper weight, etc. (it was partially offset by advertisers and onboard sales but not enough)

I can't recall the exact numbers but they were significant enough to warrant expensive external suits who eat their lunches at their desks doing the calculations and going ahead with it