Ok not reading your spoilers Silver or quoting you because then I would see what’s going on, but a well written tragedy isn’t supposed to do that to you. The classical Greek form of tragedy invoked catharsis, not grief.
The old plays often had a character become his own undoing. But it sounds like some of the fates of our companions are undeserved and are really eating at people.
I hate red herrings. Subverting Chekhov’s Gun is a dick move. There are few things more satisfying than every small detail in a story eventually mattering, and few things more disappointing than seeing all the elements of a story turn up as nothing.
If Astarion says he needs to drink a vampire’s blood, damnit, I expect the opportunity to arise. If Karlach’s entire quest is centered around fixing her engine, shouldn’t a way appear, however costly? What was the Book of Thay FOR? Things should matter more, not less, in a story than in real life.
This post does an amazing job explaining the problem, IMO.