Just came back from #Horizon ... No significant spoilers ...
I can see why this movie is inaccessible. The central character is not a person. It's a place, a small town called Horizon.
Someone (we don't know who) is printing up flyers promoting a utopia Western town called Horizon. Why? We don't know.
This film, "Chapter I," is a series of tales related to Horizon. Some happen in Horizon. Some don't. But all these tales eventually link to Horizon. (1/x)
Characters live. Characters die. Characters seem to serve no purpose and disappear off-screen. Will they return in future chapters? Who knows.
The characters' purpose is not to service the plot. It's to service Horizon.
Costner's character is just one subplot. Woody Harrelson all but disappears into his role, a Union Army sergeant.
#Horizon eventually becomes a Max mini-series, which explains the odd structure. But it also explains why theatre audiences don't connect to it. (2/2)
This is the only picture I can find online for the #Horizon flyer. Maybe someone can find a more complete image.
Doing research for my Florida space politics book, I found something similar, a 1925 two-page ad promoting land in Cape Canaveral. It promised a lot that wasn't true either.