(man-hours available of competent animators capable of being in an animation director role)/(amount of anime series that committees want made)=average animation quality over a per-season basis.
Adding more frames doesn't help when you have a bunch of koreans and entry-level japs doing them, that just adds more work for the upper-level animators who have to fix everything to conform to the models and style of the rest of the anime. The biggest bottleneck in the industry by far isn't money, cheap animators, or even time, it's the skilled animators who make sure that there's actually some kind of standard held across the whole episode despite dozens of different animators working on frames/in-betweens. The industry lacks any kind of good system for raising more of these people besides throwing more novices into the meat grinder and hoping some become experts, so it's just going to get worse if the industry insists on increasing the already bloated line-up each season.