I believe that a movie should be faithful to its source material and that such an adaptation can be enjoyable on its own. I'm sure many people who saw both IT and Doctor Sleep (as well as The Shining) are King fans and have read the original books, compared both and maybe were disappointed that the movies' endings strayed far from the books. The same occurred with Troy (you , the awful Brad Pitt movie)o. It played fast and loose with Greek mythology which is, literally, cast in stone. I was appalled with al the mistakes, especially the deaths of both Agamemnon and Menelaus during the war+ (one died at home and the other returned to Helen of Troy). Maybe King was trying to correct Kubrick, but he still should have insisted that it remain faithful. At least the TV miniseries got the ending of the Shining right even if the final scene was not.

The movie adaptations of both IT and Doctor Sleep botched the endings,. No mention of Derry's destruction, no destroying the eggs that Pennywise laid, etc. And the ending to Doctor Sleep was more a homage to Kubrick than King. that the Overlook was destroyed in the novel and TV miniseries. Also, Danny Torrance DOES NOT DIE in the novel.