I have Android but looking from the outside in on the Apple Iphone, I can see the advantage of Apple's supporting their phones by providing the IOS updates to them. It is very hit and miss with Android and for the most part the Android phone today that you buy with Y Android version, will not get an update to Android Z comes out in six months or a year. The attitude with the companies that make Android phones is if you want the new version of Android then buy a new Android phone - and with many of the carriers at or moving toward buy the phone outright or on time and no longer get a new phone for free or for a few dollars - this means no new update to the latest Android version.
I have two Android phones and an Android tablet that cost me over $300 a year ago and none are supported to get any update to any newer Android version. So it is not so much which OS is better but how the OS is supported that is very different.