Lol, that might be me, almost. I knew the movies and books existed (I think I have watched one), but I kinda doubt I remembered the writer's name. Just few years ago I made a friend who critisized the writer about her transphobic views and that's kinda how I got to know herš
(I have to admit, I'm bad at watching movies/series or reading literature and just few years ago I tried to start reading literature systematically.)
There's the Gringotts bankers being a grotesque antisemitic stereotype straight out of Nazi propaganda, there's the racist caricature character names, there's the fact that only one character in the entire wizarding world is against slavery and she drops the subject forever after everyone makes fun of her for it, probably other shit I'm not remembering right now..
Normal fantasy stuff like species representing racial stereotypes and slavery (yeah I don't get why it's "normal" in fantasy, she also did it worse then most others)
I would go so far as to say that most fantasy works that have slavery have either a "The world is an awful place everywhere, at all times, in all things" tone, or a "Slavery is BAD" tone. Whereas Rowling went for "Aktually, the slaves are happy and you shouldn't try to help them"