Comment by 0815test

Indeed, tap-and-hold is an inefficient gesture on touch-powered devices. Swipes and taps are much more convenient. (In fact, I don't even think that the gesture is used for anything on touchpads, even though it could be. Even for drag and drop, you activate it by "double-tapping" and then swiping away, not letting the double-click register. In general, UI-interaction on touchpads is quite advanced, and proves just how much ground there is to cover on mobile.)

The biggest obstacle to a genuinely productive UI on mobile, I find, is the lack of pervasive and easy confirmation and error-recovery for potentially-unwanted inputs. System management interfaces (e.g. community-built "recovery/modding" environments) get this right (everything that's potentially unwanted gets a "perform a swipe to confirm input" prompt), but almost nothing else does.