Fragmentation has long been the bane of Android. The one way in which iOS was definitively better. All the recent iOS devices get updated, they all get the benefits when new features are added. They are all "pure" iOS experiences. Essentailly, every iOS device is like a Nexus device.
Maturity, like many things, is much more complicated than a simple one dimensional trait as common knowledge implies. I think there are two main aspects to maturity which I've decided to refer to as inner maturity and outer maturity.