If not less. My educated guess is they used to get changed more often than required due to clogging, and now they’re just changed based on some minimum required.
Have you ever lived with a smoker? My grandmother’s house used to have to be repainted every other year before her death. Do you think we just “greedily cut painting costs by 80%” because we repainted it once in ten years since, or might it have to do with walls yellowing due to particulate?
Where did you even hear about this specific number in how often they used to change their filters vs now? Do you have any idea what the reasons are for them changing filters, how they decide? What the minimum is? How they measure it?
You seem to not really even understand how air filtration works.
Do all the other particulates, e.g. viruses and bacteria, drop by 80%?
No? So what makes you think the filter needs to be changed 1/5th as often?
I don't have the full paper handy (and can't be bothered to look this up just for you) but the highlights should be enough for you on this one:
https://www.sciencedirect.com/science/article/abs/pii/S00489...
Sorry! I skipped over the part where I was disturbed and disgusted at the fact that American had cut their filter expense by 80%. My friend's dad was not a smoker but was also appalled that the airline took that decision once they were free from the particulate strictures imposed by cigarettes, because he believed it made the air in the cabin filthy.
So, overlaying all of my angst about children and anti-smoking zealots, I do understand that we've all been thrown into this arena by corporations who have lowered my standard of living. Those corporations have, to be fair, raised the standard of living of people who fly with 3 sick kids to Hawaii, when from my perspective without massive credit they would be raising those kids in a coal mine. In a way, it's almost socialism.