We already know the reason for that, very few are left out of the war and those that are are either too old to fight, as in the military wouldn't even accept them if they volunteered, they are physically unable even with no age factor, or they weaseled their way out through a loophole. Those with a physical ineligibility would be too immobile to be seen very much, example, I rarely ever leave the house even outside of restrictions from the current situation because of how my house is, steep driveways are a nightmare, I'll put it that way. Those with an age ineligibility have likely grown less mobile over time, resulting in less frequent public appearances. Those who weaseled their way through a loophole basically amount to people who run some form of large company, such as Ayane's dad, who is too busy to see his own daughter let alone go out.