“The effectiveness of the escalation in war production is illustrated by the quantities of material manufactured: Britain alone produced nearly four million rifles, a quarter of a million machine guns, 52,000 aeroplanes, 25,000 artillery pieces and over 170 million rounds of artillery shells by the end of the war.”
https://www.iwm.org.uk/history/the-factories-that-fed-the-front-in-the-first-world-war
We’re not doing that in this war. Our stockpile is now depleted. So what’s next? We had two years to figure this out. The Russians were able to shift their economy to a war footing in 2022.