Just for information, how endgame is an endgame in Civilization? I assume at some point you do so well that you can't do anything else and all new nations must bow to ur immense nuclear power
It depends, but in civ 6 at least, if you don't go for science or culture, someone else will win those eventually. Usually you become so overpowered compared to the AI by the endgame that you're just waiting for the win screen to show up.
That explains everything that's going on. Whoever was playing this game won the two big wars so everything pretty much got settled out so they gave up before actually winning the game.
I ended up running a military campaign across the entire world because nobody would stop being hostile, then I eventually lost as my own cities rose against me.
It was my first Civ campaign, I played it in one go for hours upon hours until late at night.
The feeling of utter futility after complete domination is still memorable to me, it was such a strange feeling.