Tenements and social housing have been tried and mostly failed. Interest rates and taxation only have a marginal affect until they reach extremes. Emigration from an area has been shown to lower prices but at great social and economic cost.
Then there is demand, everyone needs somewhere to live. Don't just consider local demand, consider international demand. How culturally, economically or socially appealing an area is to an international audience (that is, does nearly everyone want to live there).
I view it as almost impossible for housing to improve for everyone while it is an asset and there would need to be utterly draconian or utopian changes to switch high quality housing from an asset to something universally available.