Stylus vs Touch
"The iPhone is a beautiful product that revolutionised a whole industry."
No, it didn't. It's nicely done, but it used commodity parts apart from the OS and case. The change was coming anyway. I evaluated several prototype (easy to use) touch screen phones that ran Linux before iOS or Android appeared.
The earlier PDA Qtopia was optimised for stylus and resistive screen (win95 style WIMP) the later "Phone Edition" Qtopia was optimised for finger and capacitive screen use without stylus.
The reason for PDA and later phone stylus input on Resistive screen was the "holy grail" of handwriting recognition and sketches / annotation. Once the emphasis was on Browsing and mostly information consumption rather than creation using finger input and capacitive screens (both nearly 30 years old too) was more logical.
The ideal would of course be a combo screen that can do either stylus handwriting & sketches and finger gestures. Gesture based input is pre-1988 as I worked on a Mono-touch screen project then and the boss already had a list of gestures and what they should do (I think "filched" from Xerox, which before the mouse based interface was adopted had dabbled in "pen" based gesture computing.)
iPhone was successful marketing with a very slick gui. Nothing original. No special HW either. If there was any justice and honesty and proper evaluation of Prior Art the USPO would have only awarded patents to pre-iPhone companies and only for the GSM, CDMA, 3G aspects. Everything else in all mobile phones is prior art or just "style". No SW /GUI feature should get patents ever.