There are other parts of the program beyond touches, such as scroll performance and what you do in reaction to touch events. Also the user doesn't move their finger within 85ms anyway if you think about it. That is moving to tap the phone, smushing their finger into the phone and then moving their finger away from the phone to see the result.

Nowadays you have 120hz scrolling on the ipad and the very fast responsiveness of things like the apple pencil, which shows you that responsive hardware and software is definitely possible.