The cell phone market in 2007 was awful. Even Sony’s Ericsson phones weren’t great to use and they were considered some of the best. The iPhone was massive because it made phones simple, you could use the full web on your mobile, and have all of your music on it. It was magical and pretty much solved all the pain points mobile phones had.Sometimes a product launches that isn't trying to fix a problem.
The iPhone launched not because phones were problematic but because Apple thought they could do something different. I think that's what they're doing now. AR/VR -- sorry -- Spatial Computing is just starting to take off, and Apple wants to define their niche in this emerging market.
It's easy to look back now and see what problems the iPhone "solved" in the years after it first launched and I think 10-15 years from now we'll see how the Vision had a similar impact on the market.