Overall, I enjoyed Once Upon a Time in Hollywood, but it's definitely a self-indulgent movie and a bit of an endurance test, but it has a lot of nice qualities I enjoy. I feel it's immersive in a way that few movies are right now by not just the visual production values but the sound and feel. It felt like a nice sensory trip back in time.
Also that scene where Cliff went to the ranch had me feeling very tense. I thought there was no way Cliff was getting out of there alive. So Tarantino undeniably has talent, and he knows what he's doing behind the camera.
My reading is that Tarantino was sort of fictionalizing a real-life tragedy and horrific event and using it to make this odd little fairy tale. A Hollywood fairy tale set in the 1960s.
It wouldn't surprise me if The Movie Critic has a similar vibe.