Once you get 80% of the way to perfect, you can't get much closer and even if you do, it doesn't necessarily do much good.
In golf, we see this with the ever increasing approach to some silly limit (now it is mass moment of inertia, before it was 460 cc). The truth of the matter is though, the new "technology" does something for golf club sales, but it is amazing how little individual golfers improve with the improvement in technology.
Engineering wise, the numbers make sense, but practically speaking, I can still slice the hi volume clubs to amazing length. The sweet spot is bigger, but the swing control is not improved. .