In theory, if all lines were broad enough, and all lines got enough content, without "black swans" comming out of nowhere, then I might experience the MC as my personal avatar, and feel like decisions are personal, and enjoy how the environment reacts to it.
In reality, only a few lines are really developed, many of the decisions I would take are not even an option, and sometimes the option I would take given the ones presented to me would be "none of those".
As you experience those feelings and see that the only ones that gives "points" and "tags" your character are not your options, you start to break that avatar experience, you start to experience the MC as a separate character and you see the story as an expectator and not the driver of it.
It's been a long time since I felt Sophia was my avatar, I dont feel like that anymore. She is just a projected fantasy of the writter, not mine. I'm not in the drivers seat anymore, I'm a passenger.