Eh, I played DOS2 with some friends that hated the origin character mechanic, and hated backstories. They wanted custom characters to be entirely blank slates, and didn't want anything dictated to them. I feel like the origin character mechanic gives something to both kinds of people really nicely. If you want a blank slate to imagine yourself into, you can create a custom character. If you want a character with their own unique story and personality, you choose a origin character.
I guess you want something in-between? Like a blank slate character that still has their own unique backstory? Or do you mean you want the main story to be more about your character and less about anyone else, e.g. like a "chosen one" scenario?