I mean, when they first announced the App Store, who could have envisioned something like Shazam?
History note: many things existed before the iPhone
Shazam started in the UK in 2002 on cellphones. Back then you dialed a four-digit carrier number and let their computers listen to the music. They sent the song id back to you via text message. It was hugely popular.
A few years later it became an app on dumbphones. Over 10 million users downloaded it in its first year on just Verizon, for example.
Google Maps was also on other smartphones for about a year before the iPhone came out. As were weather apps, stocks, etc. Apple didn't come up with the idea of all these apps.
Likewise for AR apps. However, there's no doubt that they'll become wildly popular on the iPhone.
Regards.