It's funny how we took both games differently. I rarely 100% complete any game, because as you said it's usually just junk to add extra time in the game. I didn't here either, but because I never got bored of the game loop, while there was still story to be played, I nearly did. My ADHD usually just gets me bored of a game, which is why I tend to play a few a time, rarely finishing their stories.
I put almost 200 hours into Witcher 3, but I bet a third of that is me reloading saves to try and get different outcomes in quests.
What are you playing these days?