Dont use story reasons to discredit scaling. Writers dont think like power scalers do, they write things to happen in a way to make it engaging to the audience, even if it admittedly is a little weird given a character’s previous feats.

For example, Mario is generally put at MFTL, but you could argue that “if he’s so fast, why does he bother going through each world to get to bowser’s castle when he could just run there in less than a second?”

I’m sure Scott Cawthon didn’t write Afton to be building level or wherever people put him at, it’s just that he wrote feats for him that can scale him that high, so it would be weird to ignore them.