But not all paperclips are the same and not all crude oil is the same either? We sort of pretend that they are for the purposes of price comparison.

And realtors do the same with houses. Have a home on the noisiest street in your neighborhood? NP, all the realtors will use comps that favor their preferred narrative anyway. Why would you get to pay less for that when that other house is available? Comp sheet doesn't say anything about traffic noise.

Rightly or wrongly, real estate largely gets treated like a commodity.

It is just a commodity where the cost of transactions have been highly optimized in the wrong direction.