I am blessed enough in my job that I have the option to pick up just about any OS I want on a day-to-day basis. I have copious test devices laying around ready for use, both Android and iOS. I also happen to be a GSM AT&T customer, so switching is as simple as swapping a sim.
I could, say, pull out the venerable Nexus 5, or perhaps iPhone 5. Mayhaps the Nexus 6 strikes my fancy one day or perhaps the iPhone 6. I even have my choice in wearables! I could rock an original Pebble, an Android Wear watch or the Apple Watch. Choice simply abounds.
And yet, day-to-day, I keep my sim safely ensconced in my iPhone 6 Plus with an Apple Watch tentatively on my wrist. It turns out that the cost to switch, even when the hardware is available, is too high to do on a whim.
Part of the lock in is due to the hardware itself. The iPhone 6 Plus has the best camera of all the devices I have. I am the most familiar with it and can have it out and moments captured quickly and easily. But, the Nexus 6 does not have a terrible camera. It simply lacks in some polish.
As a matter of fact, the lock in is not even app based. All of the apps I use on iOS are available on Android. Some of them are actually more fully-featured on Android.
In terms of aesthetics, I actually prefer the basic look of Android to iOS. I like material design, it's a pretty way to express ideas. iOS is not ugly by any stretch, but it is a bit... uninspiring in its ubiquity of conceptual verbs.
No, there are two things that lock me in.
First and foremost, it is an incredible pain to swap devices when all of my second factor auth is on one device. Even if it can be done in 10 or 15 minutes, it's a pain to have to do and is not something I'd like to do on a daily basis. It is, perhaps, just the slightest bit scary.
Secondly, there is an ecosystem developing in the Apple universe that is hard to beat. I am purely addicted to texting from my computer while I'm sitting at my desk. iMessage is a powerful driver in terms of lock in and other features, such as the ability to answer calls, are nothing to sneeze at.
Perhaps I am an edge case power user, but I suspect not. Market share of Apple laptops is rising while the general PC market is declining. iOS is recapturing ground lost to Android in markets such as China. The Apple Watch is perhaps the best expression of a wearable to date (though by no means perfect or a necessity).
There is a lot of power in Apple's vertical integration and they are leveraging it more and more with every new OS release. This is a serious driver in lock in and could very well keep me off of Android for the foreseeable future.