The biggest detriment to Danzo, both as a concept and as a character, was that he was too powerful
Like, just putting aside the same retconned "I was secretly behind every evil thing ever therefore those actually interesting societal problems didn't actually exist it was all me" shit as Zetsu, He makes no sense as a concept because if he's as powerful as he is, the story makes no sense. He either can't be as powerful and connected as he is or he's so powerful that no problems should happen to him ever despite them happening all the time. yes a whole 2 village big army along with a WMD were just able to sneak into Konoha easily, great job there shadow hokage. Then aside from that 2 akatsuki members were able to just saunter on in and Pein was basically fine until Naruto showed up, despite Danzo supposedly having dozens of extremely dangerous ANBU level ninja and being extremely powerful himself. Even if you try to justify it as "Oh, he doesn't care about Konoha the people, he cares about Konoha the place, that's why he's a foil to Naruto," He absolutely does not, It was reduced to a crater
Then, it hurts him as a character to do this shit because you can't rellay have him say"Oh I was doing it all for the village," then have him doing things that are actively working against the benefit of the village. Like, the Uchiha massacre is one thing, that's a threat to the governing body of Konoha, I.E. him. But he was also blatantly working with the greatest threat to Konoha period(Giving him Shodaime cells, infinite sharingan to play with, Kabuto). And he was sending assassins after Hiruzen, which even if he seized power immediately after, that's still a huge detriment to Konoha's rep
Instead, let's imagine a world where he's downgraded a lot. Instead of the leader of an entire army, he was just Itachi's old racist sensei from when he was a genin. When Itachi dies, he says something like "Danzo sama warned me this is how this would end, but i have no regrets" and Sasuke, he's never heard of Danzo, but he can find out, and when he does, he finds an old shack on the outskirts of Konoha with no guards, no traps, just an old crippled man sitting on the porch. He offers Sasuke tea and invites him inside. "So... I take it my student has died? Shame, damn shame. He was a good shinobi. A bit soft, but he understood duty, devotion, how to turn off his emotions for the greater good. All the things a proper shinobi needs. When he came asking for advice on what to do about that clan of yours' coup, well i told him what's what. You can't let sentiment blind you, you have to abandon humanity to save it. I told him he couldn't let even a single one of you go, otherwise you'd just cause more trouble. You Uchiha, always talking about love and hate and devotion. PA! And now here you are, causing all sorts of ruckus. Well boy, here to kill me in the name of justice? Heh, no such thing in the shinobi world"
And Sasuke...doesn't. He doesn't see some warmongering monster or a new target of vengeance, he just sees an old man spewing hate and apathy as if it was something to be proud of, as if humanity itself was shameful. He sees what the shinobi world makes, what it keeps making, what he'll eventually turn into if he keeps being a shinobi. Well not him. Not anymore, his clan won't receive justice like this, he won't receive any happiness like this. Enough going after the outcomes, if the shinobi system is what's making these monsters then the very institution of shinobi is what he needs to destroy. Maybe after that he and his clan can find peace
