The article you quote has an interesting perspective. It points to the fact that wealth is a relative concept; relative to the time in which you live and where you live.
For example, someone considered poor in the USA, would on a whole host of objective criteria be better off than a 16th Century aristocrat. Having said that there are billions of people in non-Western countries who are poor today on any objective criteria.
In the West, broadly speaking you consider yourself poor relative to what you see around you, and the opportunities you have access to acquiring material good. The better educated and more wealth you acquire, the post-materialist goals are of more importance, like intellectual and cultural development; experiential life-stlyes etc.
Of course the irony is that significant wealth is generally needed to underpin post-materialism. (An irony the enlightened Western middle classes have yet to fully resolve.)
