Ban assault air conditioner vents.
Coach seats only recline about 3 inches. The effect on the tray and leg room in the seat in back is barely perceptible.
I’m old enough to remember when there was enough room between seat rows to get out of a window seat and could get to the aisle by the center and aisle seat passengers turning their knees to the side. Now, even if all seat backs are totally upright, the window passenger can’t get out without the center and aisle passengers stepping out into the aisle.