I think the stuff that happens to your character after character creation through organic play is almost as a rule going to be more interesting than anything player-authored. This is in part me being a hater towards the "1st level character with their entire character development in the past" phenomenon as well as "player who is a bit too precious about letting anything character-changing happen to their character," especially within the context of the traditional challenge-based adventure game.
Back in the days of yore, I remember the release of a D&D adventure set in Eberron whose title escapes me at the moment. Early on in the adventure, something mysterious happens that gives all the player characters dragonmarks (enhancing those who already had one), and oh the wailing and gnashing of teeth from players who complained that they didn’t consent to that happening to their characters.
It is not always the GM who would be better off just writing a story.
Yeah, like if you have a clear idea of what you want your character's arc to be from level 1 to 20 then are you sure you want to risk sending that character into the "dice and death and random bad things happening" gauntlet?
