To me, whatever we lose in entertainment would be more than compensated for by not having wars, ever. Not having a need to make terrible weapons, ever. Murder not happening, ever. Violent crime not happening, ever. Terrorism not happening, ever. Violence being restricted to the need to kill to eat, and no other purpose.
Yes but it's because of those people, who did all that, that we now have so much literature to enthrall ourselves in. You said you don't glorify war, but the very things you are interested in, come from writers, who took inspiration from real life wars and characters in them, and shaped their mythos from the stories about them. Without the violence and savagery of the Human race and our past, we wouldn't have the fiction we have today.
Wait... Forgetting History just makes us repeat it... War is a thing all creatures have. Not on the same level of Humans but all creatures fight. Humans developed more than animals due to us have larger brains and what not and therefore our capacity to fight increased. Only thing is we've developed weapons that can end all of us, that gives us pause. Humanity is a strange creature.
Where there is life, there will always be conflict. Where there is conflict, there is drama. And where there is drama, there is entertainment, and lessons to be learned.
See, no one likes dat. Would like like it if ya were dismissed fer having an opinion? Here, let me sing you a song that will clear everything up. View: https://youtu.be/L3wKzyIN1yk
Well Humanity needs to escape Earth just to relieve the pressures upon it. Overpopulation is gonna fuck us over soon.