It’d be nice if we could easily point out in the comic that the “why” is based on who’s speaking.
In panel 1, it’s the government. Who stole land from indigenous people and gave it to settlers. In two, it’s largely private individuals or small companies. In 3 and 4, it’s large property developers who’ve bought up land on speculation, and have had enough resources to hold through rough markets and helped drive up property values.