It's overwhelmingly due to monetary policy which has inflated assets and depreciated real wages for decades.

https://wtfhappenedin1971.com/

Restrictive zoning laws preventing construction in coastal cities is also a major factor. The cities which see the greatest declines in rents have the greatest increases in supply.

https://www.nmhc.org/contentassets/f9a5ef47d06143e6b8355cfad...