'The form factor, for example, has largely standardized on the iPhone +/- some deviation in size."
That's a bit disingenuous. You have almost every vendor offering tiny 3 inch smartphoned and their range goes all the way up to 5 inches, with 6inch "phablets" filling the gap to tablets.
I don't see any lack of design variety either. Rounded or square, Metal or plastic, thick or thin, and soon curved screens are all taking part. You also have some very risky type of gimmicks, like waterproof phones and a smart watch.
And there are certainly quite a few players in the market. The big ones are the likes of Samsung Sony Motorola LG, whilst the Underdogs are the chinese brands like Oppo, Gionee and countless others