Just a guess...it is cheaper to wait until the older generation passes and leaves you property. That, and it is hard to finance a home (a matter of 15-30 years)when you have to change careers every 3-7 years.
At that rate they’re gonna be living with mommy and daddy til they’re 50.
Like me, you must have a job from the “before-times”; there is little opportunity for young people (outside of a small number of fields), and once families are off the table there is little reason to move out. Eventually they become the parents’ caretakers anyway.
I’ve been married almost twenty years, and understand why young people today are hesitant to do so; I live in a dying region (northern NJ - the NYC metro area), and this “Greater Depression” hasn’t even bottomed out yet. There is no recovery here at all, just more job losses and foreclosures; the population is being reduced to teachers, cops, welfare recipients, and illegals (retirees can’t afford the taxes). Young people are streaming out of this state; they don’t lack ambition, just opportunity.