What is the point of a class character builder if the game storyline is completely built around companions? Whatever character you create, he/she/it will always be second class to these premade companions stories.
But the BG3 story isn't built around your companions at all . . . its a new story where our main character is the driving force and making all the important decisions. All the companions are totally optional pieces.
Now the companions having more interesting backstories than our main character is another topic/issue. I don't mind it, in fact I prefer a blank slate so I can choose to be whoever I want. (I'd rather not be forced to be the spawn of a god for example!). I would however like it if we got the option to make a few more pre-selections about our history during character creation. And it would be nice if our 'origin' was referenced in the game.
Larian appears to be trying to allow us to craft the story we want . . .I mean we can start as an evil power hungry Drow and play the game that way, or be a goody two shoes, or whatever we want.