Sometimes the delay or threat of delay is enough to take a project from being profitable to being unprofitable for any local developer. This sometimes explains why you have vacant lots in areas like the bay area where any and all land would be in demand. Doesn't matter how much demand there would be if you can't afford to capture it at the pricepoint it exists at.
There's theoretically demand for millions of luxury penthouses but only a tiny level of actual demand at the pricepoint where it can be feasible delivered in any major city.
