The original iPhone didn’t have cut/copy/paste. Infamous! The quickest explanation is that I didn’t have time to do it right. I had too much keyboard, autocorrection, and text system work to do. The design team didn’t have time either. So we passed on the feature for 1.0.
The curvature of your fingers makes you think you’re touching higher up the the screen than you are. So, touches are warped to account for this. That’s why—to this day—it’s hard to target taps when you hold your phone upside down.