USA itself also had that lesson once in the WW2, notice how (for famous example) submachine guns in the USA came from the original chicago piano to much simpler M1 and even that was too complicated so M3 was made. And even for the things that get more complicated like ships or planes, design and especially production was streamlined greatly, like building the 2700 liberty class vessels of which single ship took a month to build or 175 fletcher class destroyers. And note neither of those examples were really crap all served for decades after war.

USA weapon industry now is like gutter corner of Ferdinand Porsche brain, but greedier.