Do we ever discuss this from first principles? What exactly is the benefit of private ownership of rental properties? Do private landlords do anything better

Do we ever discuss this from first principles? What exactly is the benefit of private ownership of rental properties? Do private landlords do anything better than a state-run housing agency would? If our goal as a civilization is to ensure everyone has adequate, affordable housing, the motives of private landlords seem counterproductive to that goal. Even if you can say "they'll front the money to build more units", it's going to skew towards choices like luxury units that generate above-market returns, not maximizing the number of people with warm beds. If we start from "people need homes" rather than "landowners deserve a return on investment", I'm not sure where you can make a case for anything but bulk appropriation.