Personally I think of it like a video game. Rather than parallel universes or whatnot, using the cup is more like replaying/restarting a video game so that you can make different decisions to get a different ending. So although the other timelines were technically "overwritten", they were not forgotten by the player (or in this case, the "higher beings"). They would still have the memories or records of what had happened. Therefore Jinwoo did see the final ending in which he saved the world, though not without the sacrifice of countless innocent people, hunters, and loved ones. However, this ending wasn't satisfactory for Jinwoo so he essentially restarted the game and attempted a different ending. In regards to the dream world that the previous Shadow Monarch created, I think Jinwoo meant that without the existence of the war between Rulers and Monarchs, there was no point in him being there, no goal for the player to achieve. He had built up all this power and for what? The dream world had no place for him whereas reality was where he was truly needed. The ending was definitely bittersweet to me
AHHH I SEE from that perspective it does make a lot of sense!!
SINCE THE COMMENT SECTION IS BACK I CAN FINALLY TALK ABOUT THE ENDING
Okay so, the ending was rushed but it wasn't bad, it was great HOWEVER there were s o many confusing things towards the end, which i believe is either because I thought too much of it or lack of world information in the story. So, we see Jinwoo refusing to live in the dream like facade the King of Shadows made for him, because it wasn't his reality, right? But once he defeats the monarchs, he asks to turn back time to 10 years ago. So what happened to the previous world? Did it get overwritten? Did it get completely Thanos snapped out of existence? Which can't be the case because of the tower that showed the ruins of the previous worlds. Did the timeline get separated creating a parallel universe starting from those 10 years ago? Does that mean the Jinwoo never really got to see the final ending of his own world, but somewhere that was like his world, but different? It's kinda sad if you think abt the promises he made early on