Not having a phone in the first place is the best for the environment. Failing that, having someone else reuse that phone is best. Only if all else fails is recycling the preferred option.
So of course people are going to concentrate on the problem of people just throwing these things away. And that's for anything. Not just phones.
Of course they are, and the order "reduce, reuse, recycle" are in that order for a reason-- reuse (via resale) is superior to recycling the product itself.
As opposed to what? trashing it? You'd rather throw your iPhone in the trash than just hand it to them when you're in the store already?