In CAD/EDM tools higher resolution means more productivity, (to a point) as you can fit more useful information on the screen at a time - you can “zoom out” more and still keep a useful level of detail. Especially useful in schematic and pcb design where dense areas of interest can be spatially disparate. I don’t like large screens and currently use 24” 4k screens which seem to be either unavailable or expensive, they were ~$350 in 2015 and don’t seem to have any equivalent nowadays.
The 120 Hz i don’t understand however i am not a gamer.