As they say, war never solved anything, except slavery, genocide, naziism, fascism, and terrorism...
Theres a huge culteral shift in young people these days. As a kid, nearly every lad at school had an air rifle or airsoft gun at home. People would talk about the military at school and half the lads I knew had aspirations to join the military. Now theres not a huge interest in the military for a number of reasons (mostly they know its a lot of work for little pay) and people just dont have the desire for it. I think this goes hand in hand with airsoft and most people outside of the sport see it as an old mans game outside of their own interests.
As for changing that i do think social media influence is the only way to reach younger people. There more youtubers (licking spunkstain excluded) that can post content that appeals to younger people the better. Kids now just want to play call of duty and sit around, so if more content was to reach younger audiences showing exciting gameplay then i think more people would play.