Who said anything about sustainability. We said utility, that may or may not line up with sustainability. They will pick sustai able when it has the most utility.
Similarly thry dont buy cheap if cheap is less utility. Somethi g at half the price that breaks in 1/10th the time is a bad investment, so no thry dont just go with what is cheapest. Rich people dont invest in cheap resource they invest in what gets them the most utility, which is what prfitability is.
Optimising has vision, for the thing you are optimising for.