Official character book only covers between chapters 1 to 88. This is where All Might and other heroes assault to League of Villains to save Bakugo.
So if you consider fights that Midoriya in until there, I think you can see the pattern. Midoriya usually brakes his bones while fighting. Yes, there is some fight that he doesn't, but not that much. His fight between him and Muscular is a good example.
Even if you defeat someone that is so powerful but destroy yourself in the process, that makes you a liability. You defeated one big guy, good. But if low-tier villain can one-shot you after that fight, could you really call yourself that powerful?
Only handful amount of people know that Midoriya inherits All for One. To others, he is not super powerful. Tournament Arc is a good example of it. How many pro heroes were willing to recruit him?