No, it's absolutely possible that building as a whole is not a good use of capital. There is not some fixed quantity of people-who-must-build and dollars-that-must-be-spent-building.

If the incentive disappears, the people and dollars disappear. And they have to clear a much higher bar than merely being profitable. Because it's a capex heavy industry, development must compete against other ways to invest capital (like S&P 500 or the US 10-Year).