Uh no, axis and allies produced the cheapest/most effective means to win the war. Take for instance the Stg44, mostly stamped sheet metal. Russian PPSH, stamped sheet metal.
I think GP was trying to say that fortified buildings last longer than shoddy McMansions. Which seems true given the survival ratio of castles to hovels over a millennium or so. Of course to win a war you may want to fortify cheaply... but given the modern system armies we have now I’d have to say that part of the grand strategy is to simply outspend rival nations.