Comment by cubefox

It also had a large capacitive touchscreen rather than one with a stick and a keyboard underneath, impossibly smooth scroll inertia, a MEMS gyroscope for automatic landscape mode, etc. The GUI was also optimized for the capacitive touchscreen with large buttons everywhere. Android prior to the iPhone did look more like a BlackBerry.

(One could mention however that the iPhone initially didn't come with UMTS, which was already standard at the time for higher tier phones that did cost substantially less than the very expensive iPhone.)