I think this is a matter of perspective.
The origin character backstories are only important to you as a player because you're on this journey with them. You have a front-row seat to all of their trials and tribulations, so they seem more important.
It could be argued that the companions that you don't choose to take are unimportant because if they're not traveling with you, then their importance matters less.
To anyone else that you'd come across, their origin stories wouldn't matter because they have their own problems.
I feel like we have the responsibility as the player to determine the weight of everyone's story in the game. In this case, you're assigning more importance to your companions then you are yourself.
That being said, I'd love to see a game treat our custom character as a special snowflake for once because we've never had that level of depth.
I just don't think we're at that point yet, and we're not going to find it here, so we're relegated to taking a back seat in our own adventure. I understand your frustration.
Unfortunately, we're stuck with limited options in how we present ourselves. I just hope that our choices matter in the long run as well.
If partway through the adventure, someone mentions a decision that I had made, I feel like it would go a long way into making me feel more substantial.
