I can't find this mentioned anywhere in the article, but the current imbalance of supply and demand and the resulting high prices is quite beneficial for parts of the real estate lobby which don't focus on building houses but on maximizing value from existing properties.
Approximately one in five Members of UK Parliament are landlords or have investments in the property market.
So while the article is advocating for the removal of "barriers that stop the private sector from doing what it already wants to do", it seems to be blissfully unaware of the powerful forces outside and likely WITHIN the political parties that rather prefer to maintain this imbalance...