I share the OPs views and think that the D&D ruleset and the FR setting were a big leg up here. The fact that these systems and this lore exist somewhere outside of the cRPG provides an incentive to play the game as a way of learning how to play Dungeons & Dragons. Sure D&D has it's flaws & limitation, and I'm sure there are a million ways to bag on the Forgotten Realms for being the catch-all setting that it is, but to me that's a huge part of the appeal.
It's draw and a motivator for me to try different things, again and again, since the xp/knowledge gained has those extra applications outside the game. In other words, play BG to learn how D&D works.
I also think having some of this stuff set in stone probably worked as a moderating influence, just to constrain some of the wilder ideas in favor of continuity and coherence, though that's always a double edged sword. Less likely to innovate the underlying mechanics going that route, but the upside is that more people can hit the ground running, since the basics are already familiar. This necessarily makes the thing more lego or megabloks than some bespoke Lincoln Log dollhouse, so perhaps not quite as cool as it might be otherwise in the contours, but at least it has that solid foundation. Something to build on where we at least know all the pieces can reliably fit together.
To me the obvious way to increase replay for BG3 would have been additional companions and a larger party. Also adjustments to the way the camp works, particularly at higher difficulty settings.
More art and voice assets for the custom Tav just for those subtle aesthetic variations. But mostly I think they just need more recruitable companions. There are so many characters we meet along the way you might have worked, I'm surprised we didn't get something like that for the capper. All those NPCs that can join the party temporarily, and where you feel kinda bummed when they die. Some of the villains we have to dispatch along the way, but then sorta wish I could have just persuaded them to come over to our side instead. I think it's interesting how many characters they planned to be recruitable initially and then backed way off. I mean I get it, having Ketheric around might have been problematic, but then we got Isobel just chillin' in camp for like half the game and she'd have worked for sure. But then what about Marcus? To me that's where they sorta dropped the ball. All the instances where they tease that we might team up with a villain, but then we just get left holding the bag. It happens way to many times where you're thinking ok lets team up, but then they just betray you again immediately. I could have used some more Yoshimos that stick around for a while.
Jaheira did a lot of heavy lifting for me to make the second half of this game feel worthwhile. As soon as she came on board my feelings toward BG3 shifted cause she got a deep hook in for the legacy that I really enjoyed. I think they could have done a bit more with that. I'm still salty that Viconia gave us the cold shoulder this time around! lol But in general I feel like if the character joins the party temporarily they might as well be recruitable for the long haul. If they're just hanging around anyway like Barcus or Isobel. I still think anyone from the first act would have worked, like literally any of those Tiefs or a couple select Goblins to bring on board. They didn't include enough companions to have a reputation system that held much water. There a couple party breaks but they feel sorta arbitrary, like oh you did the wrong thing so now I'm out. Whereas I feel like in BG it'd be nice to have more companions who are at each others throats, but drawing that out more with companion variety. I think they needed a second tier of recruitable companion, Non-Origin, but drawing from the pool of existing game characters. I don't think Hirelings work very well the way they're presented. More recruitable companions from the bit characters would have been a reason to play and play again. They could be limited to 3 per run, similar to the Wither's zombies, or something like that with a camp cap on the total, but some more flexibility in choosing who gets to hang out with us at camp. BG1 was pick 6 out of a couple dozen, this might be pick 3 out of a hundred, so you'd get a lot more potential combinations. I think party comp variety is the trick to replay in a BG game. That's the thing that brings me back at any rate.
For spells like Find Familiar, Summon Monster whatever, instead of random monsters from a table, to create a unique look and name them. Instead of Lupus the White Wolf, maybe I want a Greywolf the Grey Wolf. Instead of Ursus the Brown bear we might get Yogi the Brown Bear. Perhaps it's a Green Djinni instead of a Blue Djinni, that sort of thing. You get the idea. Name your Cambion more or less. Just that idea of and create a unique look like we get to do for the Dream Guardian, with some options there. A lot could be gained from a color palette. Maybe for the animal companions we get some choices for the style of barding they're going to wear at higher levels, but even just choosing a coat color would be a reason. If we get to transform into an Owlbear maybe we can choose the plumage colors, so Big Bird can have a different vibe for each Druid on offer.
Similarly for Animate Dead, maybe we get unique zombies based on the look of whoever is being raised, or Skeletons with that same sorta deal going on. You know, where they still have their old name and are wearing those old duds. Or perhaps we can play dress up with our Skeletons to give them some flare once they're raised up. Thinking about the dudes we meet in the Dank Tomb, how much fun it might be if we got skeletons with different class abilities or weapons, and then a choose a color. The Red Skeleton Warrior with a different helmet, vs the Blue Skeleton Wizard with a cool robe. Maybe I can hand the skeleton a torch and call him Candlekeeper. That sort of thing.
How much do I really need to make a BG playthrough feel unique? Sometimes not very much. It could be as simple as yet another Draconic Sorcerer, but this time the purple dragon robes or the orange dragon robes. Instead of a Sword & Board fighter with Sword A and Shield B, this time I'll try them with Sword X and Shield Y. Lots of character builds are just an excuse to use a different item or kit out in a slightly different way, use some random amulet or a pair of gloves we find along the way. When that happens, I don't need a whole lot. Some new barks and new haircut often does the trick. A color change for the portrait would also be nice though!
