The Great War killed off master, servant ( and farmhand,) alike, in huge numbers. "Without the skilled labor required to make them, complex, time-consuming dishes dropped off the menu. Cooks had long relied on imports of produce and other ingredients to supplement limited domestic varieties, ( food historian Ivan) Day says, but the war disrupted these shipments. And those fancy ice creams? Banned — sugar and cream were both among the food stuffs being rationed.
"Our food culture got incredibly simplified, incredibly slimmed down — everybody was on an austerity program," Day says."
Maria Godoy of NPR goes on to report that while other countries continued their reliance on artisanal "peasant" foods, the Brits utterly lost this, and did not begin to start to recover decent cooking until the middle of the 20th century.
Via NPR