I don’t find it so poignant. The idea of living your parent house to adult properly is cultural. Their is nothing fondamental weird about most people still living with their parents until they passed away. Sure not every siblings can benefit from it if they also want to get spouse and children. But one people arriving in a house to marry is leaving room in another one. And as sad as it is when the elders leave, their is more space for the new-born.

Of course, it is important that people are housed and not dependent of landlord but why the solution should be that every couple ( and every adult that is single) buy its own house. That’s a far stretch. Especially in countries where demography isn’t booming.