If you have a distaste for Westerns, that’s one thing. But it’s obvious that you also aren’t very familiar with the genre, and thus your sweeping statements about how this film does things that no other Western does fall flat. The rules you are referencing had been sent up for decades prior to this film. Revisionist Westerns have made antiheroes and evil white men near-universal tropes in the last several decades. The genre had been revised so since at least the late ‘60s, and by 1996 Jarmusch was far from charting any new ground on the subject.
Dead Man is a fine film, but it slots neatly into the postmodern era of the genre. It does very little that wasn’t done before, if it does any such thing. Depp’s William Blake owes his existence to James Stewart’s Ranse Stoddard (of The Man Who Shot Liberty Valance, 1962 — a film also shot in anachronistic black and white). Stoddard trod the path of atypical Western protagonist 30-plus years prior (turning an attorney into an accountant is hardly revolution). Both men go west looking to do only their job, and are forced to pick up arms instead (guarded and guided along the way by a more experienced shootist). And Sergio Leone had famously been inverting the white savior tropes of previous genre visionaries since the 1960s, perhaps most notably in 1968’s Once Upon a Time in the West. Leone also traded in the nihilism and pessimism that might — to the untrained eye — seem novel here. Something that authors such as Cormac McCarthy had turned over again and again, with a heavy hand, long before Jarmusch fancied himself a genre auteur.
That Dead Man builds on previous films and novels doesn’t make it a lesser film. But it does make grand declarations of its history-making silly, and empty.