I feel like this is easy to answer and I'm not sure why the question comes up so often.
People have jobs and get payed salaries to both build and maintain houses/apartments. Rent payments would go to pay the actual people that did the building / do the maintenance. Nobody makes profit off this. No landlord, no investor, no profit. The money goes to cover building costs, then maintenance. Easy peasy.
We have things like this. People build and maintain our public roads, schools, water/sewer systems, fire departments, military, etc.
No profits. No landlord gets free money for renting. No wallstreet investor gets free money for selling at high market values, etc.
Obviously, decisions have to be made about supply/demand, areas where lots of people want to live and all that. So what? Let's make those decisions intelligently instead of greed and profit driven.