Frankly, I think the game needs an encyclopedia. And by that I mean, it needs a way for players to read the rules they're playing by, because not all of them are going to be familiar with DnD 5e. As someone who's played a fair amount of 5e, I've spoken with a lot of players who either have never played DnD or only played earlier editions who were quite confused by many of the rules for combat, spells, etc. This could be fixed with two things:
1) Tooltips - the game needs a system that a) actually shows what kind of modifiers players are getting and b) has tooltips for those modifiers that explain what they are. This is implemented in some systems, but hasn't been implemented in some areas where those modifiers can get a bit convoluted and confusing.
2) An option to flip open the BG3 version of the Player's Handbook and see why things happen the way they happen. Basically, give us an in-game encyclopedia. Sure, a lot of players don't use in-game encyclopedias (and they're the ones who will need tooltips), but some players would definitely benefit from having a feature like this.