This is incredibly untrue. The iPhone has dominated virtually every benchmark until very, very recently, owing to a more efficient CPU, and a vastly superior GPU (the Samsung Galaxy S is pretty much the only device that beats even the 3GS).
The iPhone is always talked up on the merits of its spec sheet, whether it's screen technology, case technology, GPU speed, browser speed, and on and on. This has always been its edge.
Also, Apple has no qualms trumpeting better specs, but they frequently don't. The GPU, for instance, has been completely absent from iDevice discussion since the iPad. (It's part of the A4, but Apple doesn't tell you that.) They also failed to mention the RAM bump for the iPhone 4.
Whether or not Apple wins or loses on specs (cf. the "I don't care" bear), they're winning big on overall experience, mindshare and ecosystem. Arguments about who has the best GPU misses the point when you can only play the newest, hottest games (or whatever) on the iPhone.
It's sort of like the argument about the Wii vs. the X360 and PS3 or the DS vs. the PSP. Who cares what the specs? The apps are driving the platform.