The stakes between these two generations weren't the same at all. WWII was a real crisis where world freedom was actually at stake.
Nowadays, the wars are all a bunch of made up conflicts to help countries and their businesses keep control over world resources and exploit people around the world for money.
Well, IQ scores rise over time. Smarter people realize how dumb it is to directly kill, or pay tons for the killing of, dirt poor civilians on the other side of the world. Especially for profits most of them will never, ever see.
Edit: I shouldn't make it sound as if the soldiers of WW2 were dumb though. As another comment correctly pointed out, there's a lot of difference between WW2 and at least some modern wars.
I'm pretty sure even the inventors of IQ test say it shouldn't be used to measure the general intelligence. The only thing IQ test measures well is how good you are at solving IQ tests.
Also
IQ scores have been shown to be associated with such factors as nutrition, parental socioeconomic status, morbidity and mortality, parental social status, and perinatal environment.
Yeah. Why isn't that kid working? We need all the help we can get for the war cause. If we don't get enough Element 710 those bugs will kill more babies on this remote planet. You don't want that do you?
Wasn't there a movie where LL Cool J was the bad army guy who was using kids video games as remote controls for real war weapons? I want to say I saw it in the late 90's but it's possible my flakey memory is making this all up.
All reasonable points, however it's worth it to donate to creatives and free software projects. Part of the enshittification of the web is due to creatives being dependant on ad revenue.