The Greek tragedy that “Babylon” becomes is no surprise, it is telegraphed throughout which allows for dread to hang over each party sequence until reality rears its ugly head into these characters’ lives. The consequences of all the years of decadence and excess eventually take Sidney to a point where he can no longer participate in the studio system and he leaves the fame and fortune, perhaps the only truly happy ending in “Babylon.” Whereas Fay Zhu leaves America because of the newly enforced Hayes Code which has raised morals in Hollywood that actively campaign against her sexuality and race. St. John comes out unscathed only because of her being an observer rather than a participator, her storyline wraps up with a nice little bow and it's somewhat infuriating. For such an intrusive character to see an ending that feels unearned is exactly what “Babylon” is supposed to do. Even Manny, by the time the finale (we’ll get to that) is so broken that he leaves Hollywood entirely, the characters that Chazelle has the audience pulling for are all left broken in some way, and only the observer gets out unscathed, a commentary on Hollywood.
The endings for Jack, Manny, and Nellie are three that make sense for their characters. It's clear that the partygoer, drug, and gambling addict will probably not be making it to the closing credits alive, or that the melancholic movie star who is clearly depressed about what his career has become would not wind up driving off into the sunset. Instead, it's Manny, he makes it out alive only because Nellie eventually leaves him, finishing their crazed relationship with an ending that only the movies could get away with, dancing into the darkness. The only ending that does affect the remainder of the film is Jack Conrad, Pitt's final march to his death feels just that, and it does allow for some preparation for the viewer. However, it's also Chazelle continuing to assault the viewer with even more feelings of dread, making every step on the staircase feel like a mountain.
Chazelle is pleading to the future of cinema by the time his ending begins, the previous 180 minutes were an analysis of the past but he turns towards the future and assembles a supercut of film over the past 100 years showing the evolution of cinema. It’s a shocking decision to make at the end of a three-hour epic but it's a continuation of Chazelle knowing how to perfectly end a film. It’s a cherry on top of a film that includes Tobey Maguire doing a 1920s version of Joker, a score that hammers every scene into a beat that sets a blistering pace. Chazelle has created a film that feels necessary in an industry that is considering using AI as writers for films and would continue to be the death of creativity within film, but Disney is doing enough of that with the latest run of MCU fare that still made more at the box office than “Babylon” ever did which at the end of the day is the point it’s making, soulless corporations overtake creativity.