Just something I noticed. Text doesn’t smear nearly as much on the new iPhone when compared to my M1 iPad Pro 12.9. Text is perfectly readable while scrolling. Not sure if the nature of OLED may have something todo with it.
Someone mentioned it's because of the oled panel, testing mine out, I turned ProMotion off, scrolled through the macrumors website, the text was so blurry, turned it back on, massive improvement, loving 120hz on my iPhone.
I don’t think it has anything to do with the screen type. I believe it comes down to resolution and the size of the screen. The iPhone is 460 ppi and the iPad is 264. If you’re scrolling through sharper text on a smaller screen then of course it’s going to look better.