I don't understand why Itachi is underestimated.
Okay, his father didn't fight back. But I'm sure Uchiha clan was full of monsters waiting to act.
Village was afraid the coup will happen one day and they won't be able to handle it, hence why Itachi was tasked with said mission.
No matter how people want to twist that night if they defended themselves or not, if Obito helped.
Itachi murdered a clan full of monsters while being a mere teen.