But having a lot of easy to access food certainly does. Or what about clean water, or electricity? Or cheap transport? When has there been in the past, before the advent of industrial automation and technology, that people could just travel on a whim somewhere more than a day's walk away?
Just because some symbol of luxury like the iphone is what you think of as "more stuff", doesn't mean it is. "more stuff" is _everything_, and while it does include the iphone, it also includes the cheap phone that makes it possible to communicate almost for free with almost anyone close or far.
The tickle down has been happening for the past 70 years, and the regular people have been benefiting so much that it looks normal now. I would use the analogy of boiling a frog, but somehow this doesn't quite suit.