I’ve read both. In fact, I’ve read all 20 or so of the Dune series. Think I read all of the LOTR trilogy.
Dune is better. More believable. But then, I am an engineer by training.
LOTR is good for legendbuilding. Thrives on the emotional.
YMMV. ‘Pod
Sorry about that. Deal with it. Different strokes for all of us.
I liked the Dune series but then have realized that the author must have had a bit of snarky bit of fun, making bank on a series in which the entire universe was hooked on psychodelic worm feces! Spice blow indeed! At least Duncan Idaho in the later books reintroduced A.I. and computers allowing FTL ships without Spiced space navigation.
An entire universe hooked on baby worm feces and making millions off the books. I’ve been had! L Ron Hubbard must have ben envious of Herbert.