There are people who unironically seem to want to do that.

I figure many couples would live in one home, rent a second.

The children could have one each too, perhaps only once they reach 18.

I think there would be plenty of rental stock still.

Rental single-family homes should largely be illegal. Short-term housing should be largely limited to apartment buildings and more space-economic structures. Littering the landscape with empty houses only helps bank accounts.

Still, I'm more than cognizant that there must be huge exceptions carved out for any of these ideas.

the owner could rent out their own house and rent someone elses.

it does make sense if you want to save a nice retirement home for yourself or a place where you want to raise your children while you work and live somewhere else.

I think the idea is that nobody would prefer to rent if given a choice, and that everybody could afford to own if not for the presence of landlords in the market.