What you definitely notice between 60Hz vs 120Hz on a phone is the battery drain.

Depends a lot on the usage I guess. In a tablet where you may draw etc you can notice the difference definitely. Or if you play games on the phone. But otherwise I don't think the difference is that important as it is sometimes claimed.

Not for me. I tried out the high refresh rate thing, switched back to 60.. can't tell any difference at all. Same for high DPI vs "regular" DPI screens.

Screen flicker on CRTs with low refresh rates was terrible for me, but with modern flat panels.. nope, can't really tell the difference.

I think this varies a lot from person to person. I find the effect to be incredibly subtle - one of my monitors reset it self to 60hz a while back, and I didn't catch the problem for days.

If something is not noticeable when it gets "better", but it leads people to notice other stuff is "worse" over time, then I'd argue it's not actually a good thing to get.

Imagine if someone said "this food won't really taste better to you when you first eat it, but after 6 months you'll find other food tastes worse". To me, this would not be a selling point.

I used to switch between a MacBook Pro with a 120Hz display and a MacBook Air with a 60Hz display and never noticed any difference. I think I could probably have noticed if I'd put them side by side and compared the feel of the scrolling, but why would I do that?

There's a minority of people who really do notice stuff like this, which is fine. The problem is that for some reason, they sometimes have difficulty accepting that they're a minority.