This issue has been brought up many times already.
First of all, not all games look like that. In my current game there hasn't been a single turn since classical era without at least two nations at war. In BNW, wars don't break out because it's possible, but because there is something valuable to gain. Peace, thanks to trade routes, is profitable. If a civ has some place to expand and there is still some land beyond their reach atm, they will most likely focus on peaceful development. Unless you come to odds with at least two neighbors. They will form a coalition and attack you if it happens.
There's also an issue with higher difficulties that causes militaristic civilizations to empty their coffers in early game. In my games, many civs are on permanent negative gpt until late medieval era. This is a strong limiting factor.
The biggest problem is an early wave of DoFs. If this happens, everyone gets a positive diplomatic modifier with everyone, hence creating a boring, peaceful utopia. This will end soon enough, though. Industrialism comes, there will most likely be civs that will both want to settle the only remaining plot, some other civ will be stealing artifacts, someone else is going to win favor with wrong city states and there's always this guy who begrudges you a wonder or two.
The moment ideologies kick in, you will most likely be forced to choose sides and you'll either be denouncing someone or you'll find yourself at the receiving end of a chain of denouncements. You may also need to start a war yourself in order to cut down research potential of the technology leader or to eliminate a strong culture preventing you from cultural victory.
