I think a lot of message board types understood how to game trip timing to mostly go during low crowd level times; those just don’t exist any more, so to them it feels more crowded than ever, but really, they’re just dealing with the same mess most people dealt with for the past decade+
Precisely. I used to do three trips a year: early Oct, early Dec, and early Feb to specifically go on the "dead times" and when schools are in session.
But they stopped being dead times. The holiday party nights became hugely successful always selling out. Fall and Winter discounts moved people from the peak Summer days to the off-peak times. This was the goal of raising prices over all, but discounting off-peak.
A guess on my part is that we now have a lot more "Disney adults" that can freely go anytime they want and not get locked into a school vacation schedule.
I remember people used to be saying that WDW was for children, and my retort would be, "Then how can they be open on school days?" They would say, "Because pre-schoolers." And I'd say, "Oh, pre-schoolers 'drink around the world'?"
So, in short, WDW feels a lot more crowded to me now because I used to go in the dead times, which don't exist anymore.