This seems to be some self-help for the well-off (and their kids) to not feel bad about such dependence, but totally ignores the large population whose parents aren't affluent enough to support their children. Or may even need support from their children. I don't think the feefees of the well off is the gravest issue here.

In my experience, poorer families tend to live in multigenerational housing at a much higher rate. So this doesnt seem to be true. Less affuluent usually means more sharing of resources, not less.