Finally, the word "poor" needs to be retired. I've met lots of people with no money, and very few of them were poor people.
So I don't think it's fair to say that life is necessarily getting better in the US for low income people.
People can tell when they have things worse off than their parents. The social contract will erode in ways that people don't expect. In particular, the tidy arrangement where your retirement is in investments, so if you hurt the capital gains of the wealthy you hurt yourself, falls apart if most people are too poor for retirement savings. Suddenly, in a democracy, our retirement accounts (and the poorly hidden accounts of the actual wealthy) become up for grabs. That situation is developing quickly enough that we may well see the breaking point in our lifetime.
On quite a few of these, I think you might be shocked to discover how much of the apparent gain is definitional rather than material.
My country has salary record from 16th century. It is in gold, so can be translated to buying parity. Shoe maker today and in 16th century had roughly the same salary and expenses for living, heating, food etc.
>Life expectancy
has improved mainly by reducing child deaths. For adults it has not improved significantly, for some groups life expectancy is declining.
> abolishment of oppression (slavery, debtor's prisons, serfdom, involuntary servitude, military conscription in many countries)
Slavery and serfdom is still a reality in many countries. Even western countries have debtors prison and involuntary servitude (child support).
>educational attainment
It just caused education inflation. Person has to now study longer to do the same job. For simple child minding you may need college degree in some countries...
> standard of living have all improved.
Standard of living in most western countries is declining.
> I've met lots of people with no money, and very few of them were poor people
Maybe change social group.
What fancy measures you have. How about "cost of owning a house", "cost of getting an education", "cost of getting health care" instead of those banal measures you got there?
Nobody cares that life is comparatively better than during Roman times. Our fathers and our grandfathers lived a better easier life. In particular they had much better economic opportunities. People are upset about those opportunities evaporating.