They wanted Kubrick to direct, so it could have been a serious effort (Kubrick declined).
Peter Jackson’s adaptation was so authentic it looked at places just like my mental imagery looked as I was reading the book. That’s a tough thing to pull off in and of itself.
Spielberg would have made it campy. Lynch would have made it surreal, might have been cool but like his Dune would be a weird cult film take. (I like Lynch’s Dune but it’s weird.)
For some reason I think Ridley Scott could have done it if he could have gotten his head out of sci fi.