I can see solid arguments for either viewpoint. The iPhone was certainly a substantial leap, but a lot of innovation was happening at the time in smartphones el

I can see solid arguments for either viewpoint. The iPhone was certainly a substantial leap, but a lot of innovation was happening at the time in smartphones elsewhere and it was really just a matter of time before the advances and improvements made by Apple were duplicated by others. However, there is something which I think tips the balance toward the iPhone being a major breakthrough: the expansion of the smartphone market. The iPhone brought a lot of new smartphone users into the market, and it brought an even larger injection of cash into the market. That, in turn, facilitated a massive acceleration of R&D into mobile device technology and software. And that acceleration will have a direct impact on something that is still in progress and hasn't happened yet: the majority of the population of the developing world gaining access to computing technology and the internet, which I believe will be one of the defining events of the 21st century.