This is...ummm...dumb.
Yeah, "actor" is technically the same job; but, Brad Pitt was the lead, and she was only in a few scenes.
Brad Pitt has also been a movie star for decades.
Taraji P. Henson didn't have nearly the box office draw at the time.
Seriously, Gary Oldman is the greatest actor who ever lived, and Cillian Murphy probably made a lot more money on Oppenheimer. That makes sense. Cillian Murphy was in just about every scene. Gary Oldman was in one. It makes sense that Oldman would make less money.
Josh Hartnett made $400k on Oppenheimer as opposed to Cillian Murphy's $5 million, while having much more screen time than Taraji P. Henson had in The Curious Case of Benjamin Button. Gary Oldman isn't even listed in regard to salary.