It's a very interesting film in somewhat the same vein as 2001 - It does not provide a narrative throughline and the conclusion is less than satisfying.
An unsatisfying narrative and conclusion is a double edged sword - it can lead people to think about the film for a longer time and ruminate on it - or it can make people angry and/or say stupid things. See also https://www.youtube.com/watch?v=URo66iLNEZw
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I also think about Alex Garland's film 'Civil War'. It is very unsatisfying to never be told which side is the 'right' side, or what the war was about.
That unsatisfaction can make someone hate the movie, or it can be taken as commentary on war - it doesn't matter which side is right or what the fighting is for, no one wins a war. Winning a war is not morally satisfying. I think this is very very hard for Americans to understand, as our military tradition has centered on WWII.
I feel pretty confident in saying that no war that America fought after WWII has had a satisfying conclusion.
After 'Winning WWII' America also won the peace, which is actually why we can feel satisfied now. In no war before or since has America won the peace at anything close to the Post-WWII level.