I also want to say I agree that the threads in act 1 and 2 don't really pan out in a satisfying way, if at all, when you get to the city.
I'm curious.
Is your disappointment more to do with the overall lack of development in the stories and content more so than Larian's decision to not continue support of the game?
Since you've brought up things like cut content and disatisfying progression/conclusions to side stories. Which is more to do with overall development, rather than a continued development (Yes, theoretically continued development could allow them to add to these things, but generally free post-release content is more focused on bug fixes and balance issues)
Even games that do get continued support post release (Both in terms of free updates and paid DLC) you often still get content that is underdeveloped.
For example, in Elden Ring there's been a number of patches that have even implemented content (Jarburg and the Colleseum for example) as well as the recent DLC. But even with all this, there's underdeveloped stories (Given the DLC was mostly focused on Marika and Miquella there was a general lack of progression in other characters stories)
Meaning that even if BG3 got an "Enhanced Edition" or DLC, many of these things might still not be resolved. Act 3 conclusions to side stories might continue to be underdeveloped, cut content might remain cut (Depending on if they decide to base the DLC's location in a cut area like Avernus or the Upper City). Updates might focus entirely on new things or problems that people have with the main story (Things like allowing Omeluum to be used in the conclusion)
I mean, if I thought the game was developed well throughout I wouldn't be disappointed that they're not going to work on it anymore. So it's not an either/or thing. I'm focusing on the third act because it's where things start to fall apart a little to me. In both the main quest and the continuation of side quests that don't pan out much at all when you arrive. I suppose this would be a criticism of overall development because it seems to be a pattern with Larian.
I wouldn't expect to see every perceived flaw rectified, but I know Larian has fundamentally restructured the quests and story in the final act of their games in the past. I think BG3 is in need of the same treatment so I'm disappointed that they have no intention of working on it.
The side content is less important to me than the issues with the structure of the main quests and story though. Omeluum not being an option when there's no good reason for him not to be is one issue among many. Your choices throughout the game ultimately don't matter with the outcome of that and it feels inorganic and forced.
