What mrfuji said. You need enough for the imagination to stick. It's balancing act and the balance is off. The DOS2 origin system was overwhelming -- you were really playing their character and if you said anything out of character it felt like a mistake. And your custom character was oatmeal to their ice cream.
But BG3 is too much of a blank. Background doesn't count at all (yet). Class and race get unique dialogues but those aren't quite enough to make the PC seem unique. Any drow might say this . . . Tav needs something that sets her apart from her companions -- her own quest, her own stronghold, destiny, unique reaction to tadpole -- I dunno but *something* that makes her as interesting the others. At this point Shadowheart seems like the main character.