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
If you are in a 60 Hz electrical area (i.e. the Americas, mostly), and the power is rock-steady, and you have cheap fluorescent lighting – then anything other than 60 Hz refresh rates might improve your screen, but much more so on old CRTs than on modern LCDs and OLEDs.
These days, like most smartphone ‘features’, it is mostly but not entirely about a checkmark to induce you to feel that you are missing out on something.