I thought Lydia Tar was a real person

I love classical music, but I'm not at all familiar with the modern scene, so...
During the opening interview, it's noted that she's an EGOT, and other actual EGOTs are mentioned. She makes references to real people, Leonard Bernstein prominently. At some point, a Wikipedia page of Lydia Tar is shown. It was then that I paused the movie, went to Wikipedia, and entered Lydia Tar. The only thing that came up was a page about this movie, which revealed that the story was fiction.

But even before all that, I found much of the film to be boring, pretentious, and overlong. I fast-forwarded over some of the scenes that seemed to be more of the same. I did watch the last 30-40 minutes depicting her downward descent, and I found Cate's acting to be great, though not Oscar-worthy. I gave it a C- overall.