Note "objectively". Subjectively, their lives are worse. Why? Coddling of the American Mind is a great book that I think has part of the answer. Personally, I also think social media, general political polarization, and general grievance/doom focus of left-wing politics are too blame, in some order. Objectively speaking, their lives are better or at least not worse on most metrics, and far better than most of the world. Perhaps due to all of the above they don't have a good reference to judge against.