It's a very well-thought out movie, about arguably a quietly painful experience.
It shows you things that you can learn about lots of topics, from what it's like to hobnob with rich people, what it's like to have friends who are Jews, what the Jazz age was like, why violence and organized crime is part of society, what are the limits of what money can buy you, what is the relationship between youth and age, and whether people ever get what they really want out of life, and probably more.
But ultimately I think whether or not you enjoy the movie or merely respect it but still somehow just wish it to be over, is the relationship you have, the stance you take, towards that romantic melancholy at the end.
I would have rated this movie higher to reflect the respect I have for it, but I also wanted to reflect that it broke my heart.
I guess I would prefer all that happening to absolute stillness, maybe, but still, somehow, it broke my heart.
You have to choose your stance towards the melancholy at the end where you just have to live with your sadness.