But your proposal was "All Civilizations who have never declared war gain a global 20% increase to all outputs.", that's what caught my attention initially. The history of Prussia/Germany etc. is full of smaller or larger wars. And how far are we from the WWII? It's just a moment in the overall history of mankind. Of course they changed, but in terms of Civ6 it took just few turns from a warmonger who shouldn't get any bonus (from your point of view) to a peacufull and prosperous country, which should receive a bonus for not declaring a war? Japan also wasn't really a peacefull country throughout the history. Sure, some civilizations that were too expansionist were either completely destroyed or are not much influential now (Mongols). But other civilizations who were always peaceful had also bad endings. I don't see a clear and logical trend in this. And after all, wars have been a very important source (motivation) of technological progress, it would even make sense to make the exact opposite of your idea (bonus science while at war). Also - some countries profited from wars (new territory, resources etc.).