Apple may have taken a long while to get users upgrading to iOS 8, but it isn't having any such trouble with iOS 9. The iPhone maker has revealed that more than half of all iOS devices are already running the new software less than a week after it launched. That's the fastest adoption rate yet for the platform, if you ask the folks in Cupertino. That's certainly better than on Android, where just 21 percent of users are running Lollipop, but it's not really that surprising when you realize that Apple has bent over backwards to put iOS 9 on as many devices as possible.
Apple has a few upgrade-friendly advantages that you already know, such as a narrower range of devices (bad for variety, good for updates) and direct control over both the operating system and the hardware. However, it also decided to continue supporting 4-year-old iOS devices like the iPhone 4s and iPad 2 instead of cutting them off, as it would have in years past. Moreover, it reduced the size of the update file -- people stuck with 8GB or 16GB devices don't have to purge tons of apps and media just to see what they're missing. The speedy upgrade rate isn't so much a reflection of iOS 9's worthiness (although it is a tangible improvement) as it is the lower barrier to entry.