I love them both. The 2021 version is massive, gorgeous, and epic, but does feel a bit hollow or shallow to me somehow, in a way I can't really explain.
Maybe it is that the 1984 has a bolder vision, is more opinionated, and that imbues it with a vibrant life that's somewhat lacking from the movie that just tries to follow the book as closely as possible.
And if it failed to follow the book as closely as possible, it's Baron Harkonnen. And yet that was the most daring thing the movie did. Funny that.