Yeah, no. There is no way I'd ever sign up to fight somebody else's war requirements. Let those who dream it up make the sacrifice with their male heirs. My life it too important, short in length, and valuable for such garbage.
That's where the "mandatory" in the mandatory military service comes in (btw, I agree with your sentiment that it is stupid, the point is that you can't just not do it, you will be forced to).
Nobody can force me to fight. Maybe I would get imprisoned, maybe I would get executed, but whatever happens, it's my moral duty to ensure that whoever attempted to force me into military slavery does not benefit from the attempt, and as a conscript I would have very little to lose.
World War I is frequently depicted as a pointless war in e.g. the UK and France because of the massive number of deaths in trench warfare for just a few meters of ground. However, some Eastern Europe peoples view the war as quite a benefit due to the terms that were imposed on the losers. The modern Czech Republic, Slovakia, Croatia, Serbia, Romania, etc. would not have existed if the Austro-Hungarian Empire hadn’t lost the war.
From the perspective of Serbia's population, WWI was more of a catastrophe, even though it had a positive political outcome (the disappearance of the Habsburg Empire).
They did, tens of thousands of them.[0] There were analogous movements among the other peoples chafing under Austro-Hungarian rule. But these were minority peoples up against a whole empire, and they wouldn’t have won the day if the war hadn’t brought in enough other powers to completely defeat Austro-Hungary.
Depends, certainly how South Korea looks like today, you could say that was a success by some measures. I don't think you can really get utilitarian here, but rather societies form views around their wars.
There were sometimes more, sometimes less choices. Btw., the living speak (and we also know a good deal about what the dead thought) - not everyone dies in a war.
Survivorship bias. What you will hear will be mostly skewed towards it not being so bad because the guys who speak about it survived and ended up having fuller lives. The dead would probably have a very different opinion if they could say anything.
As I said, we know a lot about what soldiers thought, including the ones who died. (And by far not everyone who fought in a war and survived thinks it wasn't so bad - not sure how you even think that.)