It is good to have a blank character to allow people to roleplay their way.
And what exactly does that ADD to a story centric TAV ? What do you roleplay? This isnt a sandbox game or MMO. Its a STORY DRIVEN game. The story is set in stone.
Your class? (this can be done with a story TAV)
Your dialogues? (this can be done with a story TAV)
Quests? (this can be done with a story TAV)
Do you write a biography of your TAV? (this can be done with a story TAV)
There is ZERO downside of having a story TAV to your roleplaying imagination. This has been proven by dozens of RPG games in the last 35 years similar to BG3.
There is however a downside of NOT having a story TAV. You get a hollow tree trunk like what we have now.