edit: not sure most teens care or are unaware of Android's around 3 years support length for a phone.
I use Android phones, but that last points almost dragged me in a few times after getting disappointing phones.
Edit: you asked why _you_ should get an iPhone, not why teens should.
Even the worst iphone will be better than that.
I am a musician and the iPhone has lower latency. Many music apps perform better on iTunes and some app developers never even bother developing on Android.
I don't think they care either, but in many cases it makes iPhones a wiser purchasing decision, so they should care. If we're decrying the effectiveness of iPhones' marketing and intentionally cultivated and preserved incompatibilities on children, our alternative must be to encourage practical decisions. Sadly, a slightly old iPhone is often the most practical decision, because Android is still a closed platform masquerading as an open one, and they aren't kept updated outside of Google's and the manufacturers' hardware marketing strategy.
Apple is making money from the use of its phones, so (mostly) happily keeps them going far longer.