I view this as the point in structuring character definition and story development in this way. If I thought player character revelation and growth were more important than giving the player the freedom to define and express their characters and develop the other characters/storylines as they see fit, I would make games entirely differently than have been for the majority of my career.
Much of what I try to do is capture the freedom players have in playing a (good, hopefully) tabletop RPG. I have been playing and DMing TTRPGs for about 30 years. In that time, I have literally never heard someone excitedly relate the DM's plot that they played in or how they did what the DM's story asked them to do. I am not being hyperbolic. All of the stories that players related to me about their favorite moments in TTRPGs come from either the dynamism of the gameplay or from the stories they develop by flipping tables, punching quest NPCs in the nose, or otherwise fouling up/reversing the DM's plans. All of my favorite CRPGs growing up placed freedom of character definition and exploration at the core of the game: Pool of Radiance, Darklands, and Fallout -- with Fallout being the one that really ramped up the importance of player choice. And of those, Fallout had the tightest definition of the character's background, but the story development was more about how you influenced other people and places than how "you" changed.
While I don't have any problem with writing RPGs around more tightly defined characters (e.g. Geralt, Adam Jensen), that's not really the vibe of a game like Pillars / Deadfire, which is so directly connected to tabletop inspiration where everyone goes wild making characters of different races, backgrounds, classes, etc.
