Force cities to allow housing to be built, technjcally. Basically, the YIMBY argument is that the private sector and non-profit sector are lining up to build housing that will help the housing crisis by both attacking the supply/demand problem with more market supply at large and also there are specialized affordable housing builders that will directly target renters needing affordable rent.

These people are being directly blocked by municipal zoning rules like height limits and ambiguous planning guidelines, and indirectly blocked by long and slow approval processes that are costing them millions in carrying costs owning expensive property they can't build on while they fight city halls.

I downloaded this great video from Xitter of an affordable housing builder giving a deputation to the city of Toronto about this -- it's posted on my Mastodon.

https://mastodon.social/@Pxtl/110300343308877005

A choice quote:

"$20 billion dollar intersection in Forest Hill; somebody said that should be a 7-storey and 70-unit building in 2018. How...where did that number come from? Somebody picked that number. Because it "conformed to the current planning policy for Forest Hill" and somebody adjacent to the site had a backyard swimming pool. That can't be our priority in 2023."

Relevant to this, PP's housing plan includes forcing cities to upzone such transit hubs.