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.

My friend lives in a co-op apartment that works exactly like that and it works very well.

Isn't that how most apartments work? The apartment I live in, and every apartment I know of has an "owners corporation", of which each owner of each apartment is a member. The members have meetings and elect a committee to make financial decisions. All members pay fees to the owners corporation. Most of the money goes to a building manager, which is an external company hired by the owners corporation to maintain the building. The building manager handles repairs and cleaning of the common areas and facilities. Any non-routine spending must be approved by the committee (and large expenditures, such as elevator replacement, would go to a vote of all members).

...

Anyway, the gist is what you said. Individuals and families own the apartments, and collectively they own the whole building and make decisions about how it should be maintained and run.

You just described a housing cooperative. This form of collective ownership aligns owner and renter/home owner stakeholders as the same person and is a special form of consumer cooperative. Housing cooperatives are especially prevalent in the nordic countries. They keep prices down as they aren't owned by shareholders who want continuous profit. The problem with this style of firm is that they tend to dissolve after the tenets collectively pay off the property and seek to sell rather than maintain or expand the cöop. This occured after world war 2 in France as a bunch of post war building were quickly built and the coops that built them were dissolved.