Very good points. Even getting one’s own apartment is a good start, as I keep telling #1 Son.
I suspect many parents, especially those in areas zoned only for single-family homes (where conversion to a 2-family isn’t allowed), would rather the kids stay & save rather than end up living in a large half-empty home. My children are still teens, but in my area I can’t see them getting an apartment of their own for a long time.