Do you believe that you can't see the difference between 30fps and 144fps?

I can see the difference in between 30fps and 60fps.  You'll notice ghosting within 30fps at times that wouldn't happen in 60fps.  Higher than 60fps you wouldn't see it.  You would feel it, smoother gameplay.  But if your monitor can't handle it.  It will be a bottle neck.  With screen tearing your frames will over lap looking like horizontal lines flickering up and down your screen.

Depends on the person and game.

lets put it this way , the human eye can only detect at 15 fps or less , 30 fps you cant detect each picture , at 144 fps , is a waste of time and money . 

I actually prefer 24 frames per second for movies and TV, but I do almost no gaming.

It was proven and established decades before you were born that the human eye sees anything above 30FPS as fluid motion.

What you are actually seeing is the defect of digital formats when using analog eyes.

The ONLY possible way to take full advantage of 144FPS is by having your eyes removed and digital ones installed

It depends on the individual person. 

Some will see an improvement and others won't.   

As you say, you can't really see the difference in frames per se, your eyes don't 'refresh' that fast. But the actual game your playing is far more responsive as more frames are being pumped out. 

I was of the belief there isn't much difference between 60fps and >60fps. Until I built myself a decent system and boy was I wrong! 

Doom eternal, for example, on the PS4 just feels so sluggish and slow now compared to 150fps on the pc.