Vienna illustrates that there can be a decent standard of living or at least cost of housing, at medium density. Nobody is arguing that. The argument put fort

Vienna illustrates that there can be a decent standard of living or at least cost of housing, at medium density. Nobody is arguing that. The argument put forth is that SF needs to increase density as a matter of pragmatism, economics, even humanity - which is rubbish. Your Vienna example provides no evidence that that level of density is in and of itself somehow going to provide better housing costs, or anything else frankly. There is zero evidence that building higher in SF will ease housing costs, especially in an aspiration city a zillion people would like to live in. Moreover, people have every right to chose the conditions in which they live. The residents of SF can chose whatever density they want, it's their city.