I was pretty shocked by the eyestrain difference I felt going from 30hz to 60hz with a 4K monitor while only doing coding tasks (i.e. text and mouse, no real graphics or animations).
I recently went from 60 to 144, also on a 4k (27") monitor, and to me too it has been a very noticeable upgrade. No tearing of any kind when dragging windows around, and scrolling feels buttery smooth.