Simple.
Wall Street makes sure via their puppet politicians in both political parties and puppet media that enough lower to no skilled illegal immigrants continue to flood into the country that mainly puts pressure on our least expensive housing causing lower income US citizens to push up into limited lower middle class class housing, that in kind causes middle class citizens to put pressure on upper class housing, the only housing that real estate and bank corporations will build.
So more immigrants indirectly equals more buyers that can only afford what they are willing to build. Additionally they allow wealthy people from across the planet including extended families, to move into most US states no questions asked, by purchasing upper class housing that also causes housing cost inflation. It's a game and we people are the prey.
Canada figured this out so began preventing foreigners buying up their homes. But the US is controlled by Wall Street, so has politicians and their media just continue to blurt out like we are all stupid, "we need to build more housing". And they do but not the affordable low end kind we need.