When it comes to high refresh rate monitors, seeing the difference is not nearly as noticeable for an average user as it is for competitive gamers. For esports gamers, these small differences play an integral role in winning competitive games, especially FPS games like CS:GO, Valorant, Overwatch, Battlefield, Fortnite, and PUBG.
The quality of the image will not improve, it is the fluidity of the motion and the perceived blur that is improved. A 60Hz monitor will display 60 different images per second while a 120Hz monitor will display 120 different images per second. In other words, Hz is the refresh rate and has nothing to do with improving the graphics whatsoever.
Similarly, this means 120Hz and 144Hz monitors give gamers the opportunity to make faster reactions when compared to a 60Hz monitor.