It's less any technical breakthrough and more a concerted advertising campaign and collective hypnosis AKA a fad. People just decided there were all going to buy iphones. That's why the biggest threat to iphones is the trend of people buying dumb phones.

Having a "Great" product in this terms makes you subject to the whims of the crowd. As soon as they realize that your product is negative value, and/or they run out of disposable income, they will stop using it.