Thanks for the question, I'm happy to give my perspective:
In the 1950s, the reason that the US consumer was able to afford a $10,000 house on $2,500 of yearly gross income is because A) houses were available at that price and B) income was available at that level. If you fast forward 70 years, A and B are a lot less true, but I would like to focus more on B.
High wages are not available for the majority of Americans (e,g Amazon warehouse employees, not doctors and software engineers) because of two reasons:
1) Middle class manufacturing jobs have rightly or wrongly been shipped overseas
2) There are no American companies capable of employing 150 million Americans at $100,000+ per year. Instead these American companies are collectively only employing a few million people at most.
The result is a two tier society, with a small group of rich individuals and a large group of poor individuals who rightfully are wondering how can they obtain the money/"luxuries" of life like a house, a car, good medical insurance (or fair medical prices), vacations, good schooling, etc, all of which were possible in the 1950s.
The answer sadly, for those who are not gainfully employed, is that they need to somehow find a way to land a $100,000 a year job, which is not easy when there are not many on offer. Like I said earlier, I'm sure 150 million people could learn how to code or be doctors, but I very highly doubt that the government and corporations that control this country would ever want to see that happen, because of course they are the ones who need to pay the salaries.
The de facto result of all this is that corporations and governments find ways to cut expenses by cutting services or outsourcing jobs to cheaper countries with cheaper labor.
It is a political problem that can only be solved politically, unless the world suddenly decided to start engaging in technological subversion of worldwide systems by choosing Bitcoin instead of Visa, bitmessage instead of Facebook, and solar panels instead of grid electricity.