I once heard a quote by G.R.R. Martin about "Good vs. Evil" plots in fiction. It amounts to "It's a shame that the last big war of human history was World War II, when we really were fighting a dark lord with minions dressed in black and being indiscriminately terrible. The vast majority of wars aren't like that."
You could see how he deliberately tries to subvert "Good vs Evil" in ASOIAF, where almost nobody is really black or white, they tend to have at least one dark flaw and one redeeming quality. What if, however, the Second World War never happened at all, and it was the Great War that stayed as the go-to 'formula' of conflict that influences pop culture?
Would Black and White plots be as popular or stay as popular for as long as they did? Would war stories focus less on civilian dead and more on soldier dead, without things like the Holocaust or area bombing to take influence from? Would ifferent genres be more/less popular? What about the comparatively more trivial stuff (I'd imagine Hollywood would have more competition if Europe, the USSR and Japan weren't bombed out husks by 1945)?