"Watching the pendulum swing from expensive, high mass and complicated back to simplicity, low mass and thoughtful is exciting."This is really multi-layered thought. I think it is correct in the end.
iPhone, becoming a primary music source for many, is not exactly cheap and is only one source.
High mass, bulk, is definitely going away. Even very expensive components are these days often relatively small. It used to be, the heavier the better.
Complicated turning back to simplicity is true, when it comes to ease of use for the final user. It does not seem so simple when taking into account technology implemented for simple common, dare I say "most common", way people listen to music these days. I suspect there is way more sophistication and engineering/designing (pick your favorite word for "inventing" or similar to it) going into a miracle of music playing via Spotify, or an African Internet radio, on an iPhone than it is going into a nice old-fashioned system, even the heavy "over-engineered" one. Just my guess. It may be a mistake interchanging "smaller" and "simpler".
It may be a wonderful time to explore the music, but it is not because it is simpler deep inside. It is because it is much more complicated and many bright girls and guys made very complicated things simple for us to use. That is thoughtful, indeed.