Because we never SAW it. The entire thing was TOLD to us through Sync's narration. We didn't get to see this develop. We didn't get to hear Laura's own words or perspective. And then she FUCKING DIES (in a setup which comes uncomfortably close to fridging) and the whole thing doesn't even matter in the end because she's reset back to where she started with no memories of the events. She is literally existing as nothing more than a prop for Synch's character development. THAT is what "without agency" means.