In the past I always wanted the latest iPhone, as did many, hence the massive growth in Apple's sales, I don't know anyone (personally) who is actually that excited by these new offerings. It may be different outside my friend/family/colleague bubble of course.
We also need to consider that almost everyone in the markets where people can afford a smartphone already has one, so there is a market saturation. The other big markets (India, China, South America) will not so easily get swiped away by Apple due to the super high prices. So at some point Apple may need to address this if they want to expand further.