Total War: Warhammer 2

I have not messed with ME campaigns. What do we mean by “won”? I have avoided them mostly because as I understand it there is no way to win; it is just a sandbox that goes on and on and you pick a point to stop playing. Am I wrong? I know there are short and long objectives, but I was under the impression those don’t have a clean ending like a cut-scene or summary or anything. I have stuck with the Vortex ones as there are clear directions, cut-scenes, and a definite ending. I would probably try some ME if it too has a clear “win” point.