I'm getting the feeling you haven't played in a pretty long time.
Infusing blues isn't going to get you far.
There's the sleeper simulant quest, there's the exotic sword quests, there's the khvostov quest, there's the no time to explain quest (requires raiding), there's thorn and the chaperone and touch of malice which is super fun with the calcified fragment collection.
Again, even the basic story missions are substantially longer than 12 hours (closer to 20 if you rush it) not including story missions you unlock after "beating" a dlc even if you rush all of them.