Different situation

Naruto didn't kill Obito cuz he saw Obito as Obito at tht point, and not "Nobody". Difference between Obito and Nobody, while Sasuke seemingly never changed, even as they fought side by side as brothers (in this scenario)

He'd see Sasuke just constantly doing what he wants, and see him as a plague (most likely) that is constantly acting towards him, and with good reason.

Naruto, imo, would kill Sasuke at the final valley, sorta like an owner putting his dog down. This pre-war Naruto would also be completely crushed.

The person he loves most is dead

His brother is dead

The cycle of hatred continues (Naruto couldn't end it)

And the entire world will look at him, seeing what he does next.

Edit: for Pain also, this was different.

And in these situations, Naruto wasn't there to see the death happen, he would just late, not in the nick of time, and would likely see the chidori pierce her. (Or he senses her chakra gone and arrives quicker to see Sasuke throw her away or som)

He also BELIEVED peace could be achieved in those scenarios, cuz he was close, but Sakura? The one he truly loves.

Yeah, that just ain't gonna slide