The Coens are masters of genre filmmaking. Probably even more than Spielberg, they have tackled so many different genres and sub-genres throughout their career, there's nothing that is beyond the grasp of their talents. In Ballad of Buster Scruggs, they have made 6 short Westerns, not even loosely connected with one another, each belonging to different pacing and sub-Western categories. If anyone could achieve this feat successfully, it's them. It's not the juggling of dramatically different tones one after the other that holds the film back but surprisingly it's the writing.
The film starts off in quirky fashion, a comedy musical Western story around a chirpy Tim Blake Nelson as the eponymous Buster Scruggs, followed by an irony-filled dramedy Western starring an interestingly cast James Franco. The following 2 stories are much more drama-oriented and slower paced but Coens are in fine form here as well, taking each story to its desired conclusion.
It's the last 2 stories where they lose the plot a bit, particularly the final one starring Brendan Gleeson, that was so extremely out of the blue and completely ill-fitted with everything that's come before that the film ends on a dour note. Nonetheless, Buster Scruggs is fun while it lasts and another diverse, if not particularly noteworthy, addition to their awe-inspiring filmography.