http://www.goldchartsrus.com/chartstemp/USHLSPOG.php
You're right - this is even stronger evidence that whereas most people believe houses have increased in value over the last 5+ decades, they have at best remained the same value, and the price increases have simply been the devaluation of the dollar (which incidentally increases in supply at the same rate as house prices increase - roughly double each decade)
Gold is great for people who already have wealth. (Those people also have had other good investment options.) Gold is useless for people trying to earn money to pay for a mortgage for housing today.
Also, houses built today are much more valuable (cheaper per "foot" or "room") than houses built new in 1970-- they are much larger.
not to mention new materials and insulations/energy efficiency, fireproofing etc. All of these things are improvements - it's just "invisible" because people who claim the opposite just don't see it as an improvement (aka, they take it for granted).
It is the same with a lot of other "wealth" increases - it's invisible because that wealth is available to everybody. They only see it as wealth when said wealth is made only available for themselves (or wealth that someone else has that they themselves don't have).
We probably value air more than anything else, but it's worthless.
Economic value = demand / supply. Simple.
It can be useful to think of economic value as a more abstract form of energy - a "monetary energy" - with the same conservation-of-energy properties. For example, if I create a TV that's better than all the existing TVs, the economic value of my TV is sucked from all the existing TVs which are suddenly worth less and contain less economic value.
Have you actually examined these numbers? From my quick check, it doesn't seem to be anywhere near true. In 1970, Gold was $35.96/oz in 1970 USD. The average house was $23,400 in 1970USD. So 650 oz of gold would get you a house. Today, 1 oz of gold is $2,063.76 in 2024 USD. An average house costs $395,100 or 191 oz of gold. Houses are significantly cheaper with respect to gold today than they were in 1970.