A lot of good points have been raised in this thread.
To me one of the (many) problems with this game is that there is too much in it which doesn't need to be in it.
The main story involves the Dead Three but virtually every deity in the pantheon is featured to a greater or lesser degree.
Apart from name-dropping, what is the purpose of Volo, Elminster, Jaheira, Minsc or Viconia? I could add the Harpers and the Zhentarim.
I'm currently on my second run after I broke my first game (my fault) just before Moonrise Towers. I finished the monastery and creche last night and was left even more confused about the Dream Visitor, Vlaakith and the artefact than I was before.
Khaga epitomises the phrase 'loose ends'. After the goblin threat has been removed and Halsin freed, etc. she just stands in the Hollow staring off into space with no dialogue or anything. Why does she stand in that spot? She was never anywhere near there when she was part of the story.
There's also the goblin in the Blighted village who just patrols up and down through the village even after you have killed everything in there including the goblins outside the other entrance.
I think you've hit on something really interesting here. I think for a crpg having some extra fluff around the story is good for it, helps flesh out the world, but BG3 does include that stuff in the wrong way, though I disagree that Jaheiraand the Harpers are in that category. Having done a playthrough where Last Light falls fairly early on, without them the area feels a lot more lonely and lifeless. Not in an atmospheric way, but in a very dull way. They're a much-needed injection of life and interaction and again, they fill out the world.
A much larger offender is... well, everything that happens before the start of the game itself. The inciting incident of the game is an utter shambles with a timeline that barely makes any sense and is almost more holes than plot. A story doesn't need to answer every question, but it should answer most of them or at least leave those questions in such a place that the answer clearly isn't important.
For example let's start with a simple question; why was our party tadpoled? On the surface that seems like a simple question with a simple answer that barely needs going into. But then you learn more about the events leading up to your escape and you realize that it doesn't make any sense why any of the party were abducted. Frankly, I think the only explanation is that they said the opening cutscene, which they used as one of the earliest trailers for the game, was going to be the opening cut scene, and for whatever reason they didn't want to change it after the story got altered. And considering how far back they made that statement, it was probably always unwise to lock themselves down like that so early. One could theorize that their story problems started all the way back then even before the Guardian rewrite, settling on an opening scene that got locked in place and then any other change had to somehow work around. Honestly, if you think about it it's not so crazy a proposition. The fact that a Nautiloid attacked a major city never gets brought up. No one ever explains why the Nautiloid attacked the city, no one in the cult comments on it, almost like the event doesn't really have a place in the story and only serves to complicate things further by it's existence.
There's even precedent for this kind of decision being made by Larian. Just lookat Shadowheart's prism, which they bent themselves in knot strying to get into our possession while also making sure Shadowheart always started out having it, despite the most obvious answer being "have us start out with the box ourselves. And ironically, the prism doesn't even end up playing a role in Shadowheart's arc. It simply does not matter to her story that much.
