Tolkiens work stand the test of time and give that they are under the 75 year mark one could say wait and see if they last. I would say accept them as having lasted. And why ? Well they are great adventure stories , action stories. BUT also stories that work on the level of the struggle between good and evil. They are a world both alike and different from our own. Yet if one reads history, especially that of the last 75 years , starting from when Tolkien wrote "THE HOBBITT" one sees not 1 for 1 paralells but similarities between Middle earth and this earth. The movies make it clearer, the flight seen to Helms Deep remind one of France 1940 or Saigon 1975 . The movie has Gandalf statin " the battle for Helms Deep is over, the battle for Middle Earth has just begun" Well in June 1940 Churchill used similar phrases after the evacuation of Dunkirk.
But all this undergirds a story that is of truth friendship and loyalty to do what one can and then go beyond it.