Though adoption of iOS 8 has been slower than iOS 7 adoption rates, Apple is still way ahead of Android. The latest version of Android (5.0, aka Lollipop), released in November, is currently only installed on 1.6 percent of Android devices.
I’m curious how much of the fracture in Android updates is caused by the fact that most people don’t care if they’re running the newest version or not. At 1.6%, it’s almost impossible that it’s caused by anything else. There are plenty of devices that have been updated to 5.0 with more coming each day.