Now I think the main challenge is representing the player character. I like that Baldur’s Gate connected you to your characters even outside of dialogue trees and subplots.
When your characters go to battle, even in a modern 3D game you often aren’t connected to the expression of your characters.
The hidden effect is that characters stick in your mind in a quick simple way, before you really even get to know them they are already interesting. In many ways this was a crutch for the lack of expressiveness of the 2D player models, something their catch phrases also padded out. The magic of the Baldur’s Gate portraits is that each one really conveyed a memorable quirk or tell of the characters personality.