It is not a real supply shortage: number of families has not gone up and number of homes has not decreased. It is just increase of demand side, probably due to the printed new money and income increase. People could just live as before but their appetite has grown and it pushes demand up.

NIMBYs, mostly.

Is there? Every time I've looked into this the numbers don't tell that story.

What we do see is landlords (corporate and private) taking things off the market on purpose to keep prices up, in addition to the collusion this thread is actively talking about.

By every conceivable metric housing has kept up with population.

Shortage? No.

Constructed scenarios that force people to lower their standard of living so landlords can make more money? Yes.