For some reason as soon as I get to the “end” of the game, I completely lose motivation to play. This happened with DOOM: Eternal, Sekiro, Bloodborne, Paper Mario TTYD, Cassette Beasts, Shovel Knight, Oblivion, Baldur’s Gate, God of War, Mass Effect… Pretty much every game I’ve ever played. It’s like the fun part was the journey, and I’ve seen everything the game has to offer, and I just don’t really enjoy the ending process. Feels like a formality at that point.
I’d 90% a game and then put it down. Beating a game bummed me out like leaving a friend’s house after a long fun sleepover. So I’d usually wait till the sequel was announced or available before I’d finish out a title as a way to get hyped for the new release.