I would argue that a lot of iOS smoothness feeling comes from the simple fact that somebody implemented a blazing fast routine for panning/zooming a static bitm

I would argue that a lot of iOS smoothness feeling comes from the simple fact that somebody implemented a blazing fast routine for panning/zooming a static bitmap on screen based on touch input. For example on web browser you don't need to constantly re-render the page when user is dragging or pinching. Just move around and zoom the static image. Once user let's go, then you redraw the page.