Even the "open road" gets less open every tick. I think people who want to capture the Old West ought to go & drive from, say, Wichita to Taos, preferably in one straight charge. Wonder about trying to get a horse across some of those rivers, much less an entire herd. It's still possible to trace much of the Santa Fe Trail, including the bypass to the east around the worst of the mountains.
I drove from Minneapolis to Santa Fe (one direction or the other) no less than twenty times post-1999. Each time, Wichita felt a little further westward, & the oases were slightly larger & more frequent.
It's not enough for a tale to be set in the West, or to have horses, or livestock, or rustlers, or gunfire. If it's set in a city, where the veneer of Civilisation has grown thick & leathery, it's Henry James, not Max Brand.
Is it dead? No, but the audience has wandered away for a moment. The action/adventure genres aren't mainstream, & their popularity has waned.
While I'm thinking of it, folks might enjoy reading Richard Brautigan, The Hawkline Monster: a Gothic Western. It's wonderful strange, & somehow manages to capture the feels of Western, Gothic, horror, & (yes) Henry James.