The software. In the mobile-first world, software developers seem to target iOS first, then mobile web, then Android. Android has all the apps most people need, but it's just hard to go outside that short list of apps to find anything else.
The security. I'd consider myself very security conscious, and there's just too much on Android that I find unsettling. And I do keep up with Android, as I'm always curious about it. For example, a friend recently installed Snapchat and freaked out about the permissions it wanted. On iOS, Snapchat prompts the user for each permission, so you're actively aware that it's doing stuff. On Android, this information is presented in the install screen, which most people treat like a terms and conditions agreement and just blow through.
Seamless integration with my Mac and other Apple products is great, but android can do a lot of this stuff, too. iCloud is greater than people realize.
The best smart phone camera. I don't understand how this is, but every time I see a picture or video, I can immediately tell it was taken on an Android. It's as if Android phones can't just take a photo and not run it through some weird compression process that makes it look like a low red JPEG. No matter the hardware, all of my android friends have grainy low res Snapchat/Facebook/Instagram photos. Even in well lit settings. Meanwhile, my dad has a photo taken on the original iPhone printed and hanging in his office and it looks like it was shot on a 2007-era economy DSLR.
The fact that if it ever starts acting up, since it's the most popular smartphone brand in the world, I can easily find the solution with a simple Google. The 2 years I had an Android, debugging issues was a nightmare. You had to Google, and in every answer (usually found on a tech forum), you had to make sure the response was for your particular hardware. I had the Galaxy S on AT&T which was entirely different than the exact same phone on T-Mobile.
Now, given all this, I'm constantly checking in on what's new on Android, because I'd love to be impressed and make the switch if it turns out it's better. In fact, every couple of years I buy a Nexus and switch. But I end up going back to iOS after a few weeks because I just can't do as much.