I don't think it's a tragedy. The overly dramatic media and pundits get this all wrong in labeling it such. Young people are simply responding to incentives to live at home longer. Living expenses keep going up relative to inflation and wages, such as home prices, rent, insurance, etc. Living at home is a good way save money, even for the employed. Family formation is expensive and fraught with risks such as divorce…
But who raises the next generation under that scenario? Immigrants, of course, but what does that say about what American society has become? This is not a “replacement” screed, by the way, but quite the opposite. If your culture requires constant immigration to survive, that means it’s unsustainable in the steady state. Like, it would be bad if everyone adopted your culture. Your culture is the panda of cultures.
Better yet, who takes care of all the old people? Nobody.