Just got a new phone (OnePlus Nord 3), turned refresh rate HUD in developer settings and I see some parts of the system and some apps display 120 Hz but I have problem noticing any difference, same with my wife’s Redmi Note 12, i have to look very carefully and maaaybe I notice some different, not sure
Diminishing returns!
To add to that, it’s because frametimes are inversely proportional to the framerate.
Every time you double the framerate, you halve the frametime. Which in turn means that the improvement in frametimes gets smaller, the higher you go.