You're picking [1] to the exclusion of Warren's own numbers. Per Warren's numbers, the increase in house size was essentially restricted to one additional room. Certainly not the 60% increase in size you posit.

The cost increase in housing was non-uniform, and the largest increases in cost were driven by houses in good school districts and we're talking tens of thousands of dollars across school catchment areas in the same metro.

Thus the increases in house prices were disproportionately leveled on families with school-age children.

Square footage could increase if the rooms got larger and there are more of them.

Things like washers and driers only add a very small amount to the typical house price.

It's not an apples to apples comparison.

Prior to the Tax Reform Act of 1986 (TRA86), the interest on all personal loans (including credit card debt) was deductible. TRA86 eliminated that broad deduction, but created the narrower home mortgage interest deduction under the theory that it would encourage home ownership.[1]

Basicly housing has been subsidized relative to other purchaces. EX: A 55" TV included with a new home costs a lot less than one paid for with credit cards.