I don't think that's true. For example, less than a year after its release, the iPhone accounted for 28% of smartphones sold in the U.S. (and presumably for a greater percentage of smartphone-sale revenue): see https://arstechnica.com/gadgets/2008/02/iphone-owns-28-perce....
And half a year after that, the news was better still: https://arstechnica.com/gadgets/2008/10/apple-officially-sur...
So... by & large nobody had an iPhone or smartphone. They all had Razrs (or other feature-phones) instead.
That's a difficult statement to support. It set the stage for everything that came after, and it knocked the industry back on its heels. I'm not sure of the margin or unit numbers but for lots of values of "commercial success", that alone is hard to ignore.
It tool them 4 generations to get there, and a lot of money.