The economy is rigged such that in the absence of any positive action, workers' purchasing power goes down over time by default. This obviously isn't a problem for the rich, whose money is stored almost entirely in assets which by definition rise in value with inflation. Meanwhile, everyone else whose income comes primarily from a wage must constantly struggle for more concessions just to earn the same real amount they did last year.
While society has gotten wealthier, have average people, at least in America, gotten wealthier? Technology has advanced so there's things that people can own now that they couldn't before, but if you look at things that are constant (e.g. housing) then it looks to me like people have gotten poorer.
