State housing has a place, but I think they really need to fix the demand side of investors. There should be significant deterant to holding residential property in large scale. While options are varied I think a progressive asset tax of total property owned. Something like 0.5% per million starting on the second million. Maybe some principle place of residence reduction. So most people can have a house even a second/third house without occuring holding tax but you stop people sitting on $10m+ in residential property, which is quite a low threshold really. And stop investors dropping billion plus amounts into the market. Then some rule about top marginal rate for obscured ownership like overseas owners and trusts etc to stop shenanigans there.
It comes down to that line about residential property has to be good for residents or good for investors, you can't have both.