Note again that my example of it working pretty effectively was for a decently sized nation and not just a small highly desirable city that wants to grow. The percentage of public to private housing in a city is meaningless to demand of people who want to live there.
I’m also not sure that Vienna counts as some massive failure of public housing, as the city is famed for its average rent being so far below comparable cities.
I also don’t see the problem with the government owning most of the apartments in a city, and indeed the more well to do citizens you can get to pay rent to the housing agency the less in taxes everyone else needs to pay.
Eventually if you build enough housing for everyone who wants to live in a place to live there, people will stop competing with each other for the limited spots. Prices are so high in dense urban areas because so many people want to live there, and so price goes up until enough people are pushed out that there are enough apartments to satisfy demand.
If you want to crash prices as you put it, you demonstrably need massively more housing than people who want housing, either by building more housing or by reducing the number of people who want to live there. If you don’t, people will just fight over the limited slots, and in a private market that means the slots universally go to the richest.
Given private developers will never willingly build enough housing to satisfy demand and therefore drop the price their units self for, it falls to an entity that is not seeking maximum profit from a given development to do so.
Around both outlying Vancouver skytrain and Toronto regional areas there is a lot of single family residential within a few blocks of stations that could be redeveloped for higher density, even neglecting that massive portion of the Toronto dock lands near the size of downtown that the government just sold off for private development. The government can absolutely get its hands on lots of land to develop, especially as industrial activity continues to move away from city centers.
The government also uniquely has the ability to build more metro lines that bridge areas to downtown, and could thusly drive density in currently cheap areas.
I just installed a sol ark system, and can confirm that they work just as well with a pi and Solar Assistant. Not open source, but integrates well with homeassistant and no need for network connecting the actual electrical equipment, just usb.