Yeah. King is kind of the same as Hunter S. Thompson, in that the writing is so engaging and visual, you don't really need a movie.
Ah ... I don't know if I'd want to review It. It would require a rewatch, and I don't really want to do that to be honest. But anything's possible.
In the meantime, I'll say this. I wanted Part Two to take things further. Going off memory, a good 45 minutes was wasted getting into the story, which isn't needed. This story has been out since the '80s, it was already a movie in the '90s. Can't we just ... go for it?
Yes, the Dark Tower is definitely his magnum opus. There are elements of horror in there.
Oh! One final thought on King. I love Kubrick's The Shining. It's great acting, a great example of what horror movies can do. I'm also sympathetic to King NOT liking it, because it really does differ from King's characters. The TV movie version of The Shining is pretty good.
But it's no match for Kubrick's film.