In the 70's, 80's you could have an average job and buy a house. Not so the case anymore
Everything is so interconnected,
Population in 1970 US - 203 million
Population now: 331 million
The median age of the U.S. owner-occupied housing continues to increase as the pace of home building falls behind its historical pace.
www.builderonline.com
The median age of U.S. owner-occupied housing stock is gradually aging, increasing from a median age of 31 years in 2005 to a median age of 39 years, according to data from the 2019 American Community Survey. In addition to an aging housing stock, the NAHB explains that the number of homes built continues to fall behind the pace of building after the Great Recession.
New construction added nearly 5.4 million units to the national stock from 2010 to 2019, accounting for only 7% of owner-occupied housing stock in 2019. Owner-occupied homes constructed between 2000 and 2009 make up 15% of the housing stock. But more than half of the owner-occupied homes were built before 1980, with around 38% built before 1970. Due to modest gains of housing construction, the share of new construction built within past 9 years declined greatly, from 15% in 2006 to only 7% in 2019. Meanwhile, the share of housing stock built 50 years ago or earlier increased significantly from 30% in 2009 to 37% in 2019.
(Simply put, there are fewer houses to go around increasing cost and ability to purchase. )