The last time I can remember minor characters getting such good treatment in a video game (and to be fair this depends on what I've actually played) was in a critically-acclaimed story-based fantasy RPG that was the third in the series, developed by a European studio based on licensed IP. I'm currently playing The Witcher 1, and a scene where I had to follow an elderly druid as he walked very slowly to the destination, made me remember The Witcher 3 where there's a famous scene where you walk with the Bloody Baron to the site of his child's grave, and he and Geralt talk in detail about his story, and the lore of the monster you're trying to defeat. I wanted to link a video I'd seen a while back talking about this scene, but I can't find it now.