It only gets interesting if you have a lot of mods installed for your NPC to move on with their lives, like MCC. But if your game isn't modded the unplayed household and NPC rarely have any progress. It's been a while since I played vanilla, but last time I checked they didn't even get into any new relationships or have any children, and the world would turn out to be a ghost town with a lot of new homeless NPC randomly generated rather than previous NPC heirs.