As we get more technologically advanced, more civilized and more refined, differences get smaller.
The Nikon SLR was in a different universe than the Instamatic. Just about anyone could instantly see the differences between pictures taken with these cameras. Taking pictures for online use with the Sony RX1 and the 80% less Canon pocket camera–not so much.
The rough peasant wine available on your table at a local restaurant was a totally different experience than a vintage Burgundy. Thirty years after that vacation, it's pretty tough (in a blind tasting) to tell the difference between a bottle that costs ten dollars at the local store and one that costs $200…
The speed difference between a Mac IIfx and a Commodore 64 was no contest. One was for professionals, one was a game for kids. Today, there's no dramatic functional difference for most users between the speed of the cheap Android tablet and the Mac Pro.
But of course, for those that care, the difference matters more than ever. For those that care, the premium available to be paid for a better camera, wine or computer is actually far greater than it ever was before.
As the differences get smaller, the purely functional reasons for premium goods fade away, and instead they are purchased for the reason we've always purchased luxury goods: because of how they make us feel, not because of what they actually do. The fur coat is not warmer than the down jacket, it's merely harder to acquire.
(Premium vs. luxury has more on this.)