writing a book and rolling dice to help you decide how some of the events turn out

I love my solo rpg experiences and this description is kinda spot on. While not writing a book, the process is there. And even if the system has great ways to generate prompts for you it often ends up in the player's hands. For example many Moves in Ironsworn have on the miss as an option "make the most obvious outcome happen".

There is also an harshness dial often unmentioned, no comments on going (too) hard on the character. How hard to make the soft moves. So yet again the author is left in control.