Soldato
This is not true
24fps was found as the LOWEST fps human eye could still perceive as somewhat smooth, chosen for motion pictures. But the higher fps goes, the nicer it looks (and feels, for interaction).
Upper bound (as in, you could still feel a difference) would be somewhere beyond 1000fps.
I would always prefer going from 60 to 120 fps to going from 1080p to 1440p, even for desktop work.
What I mean is its subjective from person to person, we have an idea that 30 is low but perfectly playable - what is interesting will be what is ample as there is clearly a diminishing return once you get beyond a value like 200fps where even the most genetically gifted eyeballs will not determine any benefit. We also have displays where the gsync/freesync hz has to stay within a range and to avoid tearing you cap. I myself play on a 4k monitor and 60fps is pretty crisp for me.