"Once Upon a Time..." is Tarantino's first film out of the Weinstein universe. All of his other films were Miramax or Wienstein Company.
He could have gone to any studio he wanted to get this film made but after multiple courtships, he decided upon Sony Pictures. They pulled out all the stops and gave him all the toys he wanted to play with.
Now, come Oscar Time, it would be a colossal embarrassment for Sony if the film were not held in high regard, even if shoved down the proverbial throat. The word on the street would be: "See, Tarantino can only make films with Harvey. Anywhere else he's a hack".
With Pitt and DiCaprio star power attached, lobbying, favour trading and future promises of not-yet-done deals pushed the film through and got Pitt his first acting Oscar (he has a producer Oscar already for "12 years a slave").
"Parasite" is out of the Hollywood ass-kissing circle which makes all its awards sweeter.
Brad Pitt should have taken the Oscar for The Tree of Life, he showed range I'd never seen before. That kitchen fight was unreal, I became a Jessie Chastain fan. His role Once Upon...was as Barney Rubble would say, "warmed over leftovers".