Recently played BG2 for the first time, so I am not going into this based on nostalgia. That game is GREAT on certain things and absolutely terrible on others. And something that makes it great is its characters and characterization. We were discussing this on the party banter topic. Your party members in BG2 have in-depth conversations with each other, not just a line apiece. Dragon Age: Origins was its spiritual successor, and influences from that game are clear here. Party banter in DA:O sometimes concerned decisions you made in the game (like a romance choice), which is a great way to make the characters feel active in the world and ALIVE. At camp in DA:O, party members would interact with each other, like the Dog and everyone else. Furthermore, you could facilitate relationships and interactions between certain characters in both BG2 and DA:O (e.g. Aerie and Haer, or arguments between companions in the games). Larian is already putting a lot of work into these characters as a selling point of the game, so why not go that extra mile?
Another thing BG2 did well was a sense of time and space. The world felt like a world, and the distances you traveled from place to place felt meaningful, even if they were just a zone and a path apart. I loved the tightness of the world in DOS2 for fun play, but I'm not sure it works as well here, when we are supposedly traveling great distances in a matter of moments, and structures we travel on aren't that big in scope. Now, that might mean the world is more "symbolic," but I think there is one location that absolutely should feel big and sprawling and bustling with great distances and dense interactions: The City of Baldur's Gate. Just one place, the title location, should feel absolutely massive, broad, and dense with possibility.
On the matter of time, I understand implementing a day/night cycle may not be feasible with the type of game Larian is making, but it would be nice if certain things shifted the lighting to indicate the passage of time. You get two short rests, and a short rest probably takes time. The long rest takes us to camp at nighttime, while the world is in daytime, so the long rest is already great at indicating the passage of time. Perhaps you can start the day in the morning, and each short rest shifts the lighting from morning to noon, and then noon to evening. It would make short rests feel like more than just "replenish slots and health." Perhaps certain events may only be possible at certain times of the day or certain characters will appear at certain times (like vampire lady at crypt in BG2), but instead of having a day/night cycle, Larian should base it on morning-noon-evening, which shift along short rests.
To echo what many are saying here: What BG2 did right was immersion. Immersion in environment, immersion in characterization, immersion in the flow of spacetime, immersion in equipment. There was a clear attempt at getting the player "lost" in the totality of the experience of the world. The Larian style of game set by DOS1+2 is more fun to be sure, but it is not as immersive. I wouldn't even argue that one style is better than the other, just that they reflect different priorities.