One big problem is the way homes are made. It has not changed substantially in over 100 years, perhaps more.
Try to imagine any industry that, for the most part, does things the way they were done in the 1920’s. Back then labor was cheap but now it’s not.
How about a little innovation such as this:
https://www.thezebra.com/resources/home/3d-printed-homes/
“Cost: 3D-printed homes are surprisingly cheap to create, running around $10,000 on average today. 3D-printed home leader ICON hopes these homes are even more affordable in the future, with a projected goal of reducing builds down to $4,000. Once plumbing, electrical and other additional construction is added, the final housing cost is around $140,000 to $160,000 on average today.”
You really think homes haven’t changed in how they are made? During the 1970’s I think is when homes started being pre-manufactured, much like a mobile home. They build the truss, and frame with pine, put up drywall with staples, and using standard format floor plans. If you want a basement, that’s just another cheaply built one piece concrete pour that will crack within the first year. Then they just roll the house down the highway on a wide load trailer.
I think home building has changed significantly over 100 years, and not for the better. My house was built on-site in 1955 with solid wood framing (with brick on the facade) that was probably ‘green’, with a concrete block basement. Way different than what they do now.