I'm not denying that. Of course average standards are better now than they were in the 1950's. But that argument is frequently used as a distraction to avoid talking about very achievable ways that we in America could improve living standards even further, or about very real ways in which lower class people are still suffering even though they might have an Xbox at home. All of the problems I mentioned in my above comment are still valid even though a section 8 apartment is better than a tin shed, yet you didn't address any of them. "There will always be a bottom of the economic ladder" is not an excuse for the wealthiest nation on earth to still allow people to be financially ruined for visiting the ER, for example.

Also, the myth of mobility is not an entirely separate topic, in that it's another distraction frequently employed to place problems on the individual and avoid talking about systemic changes that could take place to benefit people on a broader scale.