You could say the same if you were to compare an MS-DOS computer with the original Mac OS and OS X. But I do agree with your point, the biggest advance in usability for iOS has been faster hardware and more memory, rather that more advanced software. My old iPhone 3G seems unusably slow to me now.

I don't think that should be a surprise though. OS software and development frameworks are hard to get right and easy to spoil with badly thought out changes. Apple have been there and done that, so they have a very measured approach to evolving both iOS and OS X.

Google were unbelievably lucky that they had a modern, flexible platform in Android that they were able to very rapidly re-engineer so that it could be competitive with iOS. If it hadn't been for that, Apple would have had the whole smartphone market entirely to themselves for the first 3-4 years, and they'd have deserved it. No wonder Steve Jobs was so pissed at Google.