So as we all know, in good old D&D one of the most important things about a character is their backstory, it defines how they behave, how to roleplay them, their class and pretty much everything about the character. Sadly, no matter how many pages you fill with detailed stories your characters went through that led them to be an adventurer, Baldur's Gate 3 or any D&D based video cannot interact with the character's background you've written.

Personally I really liked the mini-quests addition in patch 5, the one that gives you a little something for doing something your character would do. This made it feel meaningful when you fought the goblin pack outside the druid's grove, and all members of the party attempting to get in survived, for example.

This is what a game needs to feel like D&D. The roleplay, the need to behave like your character would, this what connects the player deeper into the game and makes the player feel involved.

I have a suggestion for a method to deploy this. You know those boxes in every character sheet that no one ever fills? The ones titled: Flaws, Bonds, Ideals, Personality Traits and Allies and Organizations. Well those boxes are the key for Baldur's Gate 3 to enable further roleplaying in the game. You see, all of these boxes are an instance of one's behavior and place in the world.

My suggestion?
In the character creation, add these boxes for players to choose from a pre-written list (perhaps from the player's handbook) of ideals, flaws etc. while in game, reward a player for acting according to their personality traits. For example a character with the flaw "power hungry" might be rewarded in some form for abusing the power of the parasites.
Furthermore, the option to add bonds and organizations makes the character a more distinct part of the world, this can be expressed by special dialog options, for example by being part of the Zhentarim or flaming fist.
One last thing, another method to perform this change is by allowing the player to choose an alignment. There are already dialog options for different alignments, and allowing the player to choose one will set in stone the character's behavior.