They can recoup the investment with volume (especially apartments) I would think? Sell 10 houses at 2 million each or 30 at 1 million each or however it breaks down.
Their land, labor, and material costs aren’t trivial. If thy were pulling a 10-20% margin before, how will increasing volume (which increases costs) make it up?
They reinvest that generous 10% to buy more tools and hire more talent to build 10x as many homes at 2%. Seems pretty straightforward to me
Taking on those liabilities is very risky when the next downturn happens and you're stuck with inventory.
you should go into real estate development and make a fortune while solving a serious social problem for your country!