I remember watching a video about a European aristocrat who was one of the first to write about the burgeoning American culture. He was worried the culture of wealthy affluent men trying to look like one of the commoners would mess with their mind; that by making a clear difference between the have's and have nots was important. When have's act like have-not's the have-not's question why they don't have money, why they don't have large houses etc etc. and feel like they should, and become self loathing because of it. They feel too much that they should have everything the have's have because they're just like them... But they're not, whether through birth, or luck, or perhaps because they just worked harder, but they're a different social-economic status then you, you should have everything they have.
Which brings me to your statement>we've gone from one where you conspicuously show off how rich, attractive, successful, etc you are to one that is superficially anti-elitist
It just seems to match that now we have to be modest, else those who haven't tasted success may feel bad about themselves.