With all his unfinished works being published. With the exception of the Alliterative Beowulf in verse. I’m surprised the estate hasn’t changed their mind about allowing other writers to write in his universe and make new novels in Middle Earth.

You have Conan novels not by Robert E Howard, 007 not by Fleming, Oz not by L Frank Baum, Tarzan not by Burroughs. Holmes books not by Conan Doyle. Literally dozens of imitations and knock offs of Burroughs Martian series.

Terry Brooks Sword of Shannara is the most obvious clone of LOTR. And with the sequel Elfstones thankfully he took that series in its own direction.

I see that Christopher Tolkien was all about protecting his father’s work primarily the legendarium itself and the Silmarillion, and he wished the films by Peter Jackson had never been made. Amazon never would have gotten the rights to Rings of Power within his lifetime period. and even that is just extrapolated from the appendices they aren’t allowed to adapt the Silmarillion. The licensed derivative works are in video games, animation and in film. No books.