There is some great filmmaking on display in Once Upon A Time in Hollywood, and there are a few great scenes where Tarantino's trademark dialogue is at it's finest. That's it.

Tarantino's engrossing character work is nowhere to be found here. Tarantino's often excellent storytelling is not in this film. Tarantino's sometimes excessive but usually fun flirtations with genre homages nosedive into painfully abundant and indulgent scenes that lend nothing to the bigger picture; a bigger picture that feels virtually nonexistent, save for a few sparse thematic threads peppered into some of the dialogue. This film's closest thing to a theme is irrelevance, but it never expounds upon the idea. Rick Dalton is washed up, and it is shown several times that Rick Dalton is washed up. Tarantino offers nothing else to the character. And it's obvious that this is supposed to be reflected through the eye of Tarantino observing his own self-waning career, but again, it ultimately leads to nothing.

And as a "love letter to the golden age of Hollywood", it borders on masturbatory. It doesn't border on it, actually. It just is that. It's masturbatory. There are copious amounts of scenes where Tarantino gets to indulge in his fantasy of directing a slick western in the 60's. And around the third time it happens, you start to realize that this movie isn't really going anywhere. The first thirty minutes are great; but that's before you realize the movie doesn't have a destination. At a certain point, you come to a harsh reality. And in his homage to Hollywood, Tarantino leans into the regressive side of things. It's established that Brad Pitt's character in this film murdered his wife and puts himself into situations where he allows himself to be seduced by underage women. And there's never a strict condemnation of this, or other regressive attitudes by characters in this film. It feels basked and reveled in. When Brad Pitt's character savagely bashes a woman's head into a fireplace shelf in the final minutes of the film, it doesn't feel like vigilante justice as it is purported to be. It feels gross. It feels icky. It doesn't feel fun. It just feels like a dirty scene with no higher purpose. It doesn't feel like satire. It doesn't feel like there's anything under the surface. It just feels disgusting.

Also, if Tarantino wanted to make a film about the Manson murders, he should've made a documentary. The alterations of historical events in this film are putrid. Sharon Tate was brutally murdered during her pregnancy. And this film just pretends that that didn't happen, and that everything was fine. The Manson murderers didn't get away with their deeds. Why are the Manson murders even depicted in this movie? How does that relate to what is seemingly the main story here; Rick Dalton and Cliff's descent into irrelevance? And what does changing the course of history add to this? Tarantino so desperately wants this to be okay; in an interview he said that because it's technically a historical event, it's okay to depict it. Sure. That's true. But he's not depicting it. He's depicting a falsified version of historical events; a falsified version where a real pregnant woman wasn't brutally murdered. For entertainment. Not for me.

EDIT: I am aware that Tarantino has altered history in the past and it’s nothing new. However, it all depends on context. Killing Hitler in Inglorious Basterds is much different than pretending that a murder at the hands of a vicious cult that still holds personal effects for people living today didn’t happen. It feels handled very poorly, here. 

I haven't seen Death Proof or Jackie Brown, but with that being said, this is easily Tarantino's weakest film. It lacks the action film precision and laser-focused storytelling that made the Kill Bill films so great. It lacks the intriguing mysteries that made The Hateful Eight and Reservoir Dogs so great. It lacks the amazing character work and structural futzing that makes Pulp Fiction a classic. This film has next to nothing in the way of theme, the characters are some of the weakest that Tarantino has ever written, and it's aggressively indulgent and overlong because of it. It is definitely the most inessential Tarantino film, and I don't think I have any desire to see it again.

Not trying to yuck your yum on this, but I wasn't a big ol' fan of this one!