I never complained of stutters on iOS 7 for my 4S and Air 1 at that time. Few reboot and app crashing problems aside, the animations were consistently smoother. The touch response was fast, accurate and predictable.
With iOS 8, I accepted that old (non 64 bit) devices up to iPhone 5/5c may not have the GPU capability to render those transition animations at 60fps.
But from iOS 9 onwards, same animations started to appear stuttery and touch response got worse. Touch accuracy has gone down considerably. All this on powerful devices like Air 2.
Apple Apologists can live in denial all they want but planned obsolescence is for real.