> Again, individuals may disagree but society at large has decided its of enough value to keep in existence.
I firmly believe that's the other way around. Society has ybo say about whether military should exist.
There are always people who prefer to focus on arming themselves and extorting others. Either by threatening or offering protection from threat, which blend together.
People argue whether goverment rules the people, or if the people are actually stronger then goverment and goverment rules just because people will it.
The truth becomes apparent when government and people can't keep stable relationship between themselves and ability to collect tax is threatened. Then the military steps in and supports either government or the people.
That's because the only reason military allows goverments and people do what they do is that it results in steady stream of taxation that military can feed on.
Of course people also benefit from tax being collected in stable and predictable manner instead of military just roaming their country and taking whatever it desires randomly.
Nations, armies and goverments are most advanced mechanisms of keeping human violent extortionists and most dangerous technologies from interfering with the economy.
It's of tremendous benefit to our civilisation, except for two world wars which I hope were enough for militaries to learn that they can't efficiently steal economies to extort from neighbouring militaries.
But nontheless if you join the army you join the organisation that's freeloading on everybody else while sharpening teeth that will be used against them if they misbehave. Until you stay there you are golden. But if you plan to rejoin the rest of the world at some point, time spent in the military will be at best wasted years for you and cause of much damage to your life and psyche at worst due to conditioning and abuse you underwent.
Can you get something good out of it? Sure. But how many ex-military end up in dangerous jobs or without purpose in life outside, treating damage done to them by military with opioids? You probably don't have them in your social circle but I'd say there are at least a few for each one of your ex-Marine friends doing charity.
This belief of mine is mostly based on concept of "monopoly for violence" if you want to read more about it.