Apple's win with the iPhone wasn't the concept of "smartphone", but the concept of "humanist UI design".
The idea of scrolling, zooming, pointing and manipulating objects as if they were paper on a roll, or physical buttons eschewed the previous generation of phones which used a stylus and scroll bars down the side of the window.
It's this humanist user element that represents the revolution if the iPhone, rather than the anything of the "smart" features, which people rightly point out were rather underwhelming when it was released.
That might be overstating one thing, however. The one other innovation was the integration of a full Safari rendering engine, as it was far better than comparable phones at the time. Other vendors assumed that the UI would be too clunky to display full pages on a small screen. Apple, again, worked on the UI and made it work.