John Wayne is irreplaceable. That said, I think Jeff Bridges could do a creditable job playing Rooster Cogburn. I’m really curious to see how the rest of the cast shapes up.
Loved Wayne in TG, and Duvall was good too. Glen Campbell, not so much. Kim Darby's role could have been played better by the little kid in Lost in Space. (Sorry Bill M.)
True Grit is iconic, but John Wayne made so many better films and deserved the Oscar for earlier work.
Red River, The Searchers, North To Alaska, Rio Bravo, She Wore A Yellow Ribbon, The Quiet Man. So many others.