You make some valid points, but I disagree here:
Has all the advances of the modern world made the people of the US happier, healthier, longer-lived, wealthier? No.
Improved medicine, public health and sanitation have statistically lengthened human lifespan very significantly in the past 120 years or so. Infant mortality is way down and people live longer in general. Those are facts. Also, the modern American works fewer hours and under safer conditions than his predecessors. As for happier, that may be debateable.
You are quite right to pick me up there ;) There have been many incredible advances from which many people have benefited.