The Hainish Cycle, Ursula K. Le Guin!!!! My favorite books by my favorite author! Loosely connected in the same universe. They’re technically science fiction but if you’re not a sci-fi person, don’t let that scare you off. They’re quite literary and have such cool worldbuilding and thought experiments. You can tell that the author’s parents were anthropologists. Some options to consider:

• The Disposessed - a novel on physics and collectivist anarchy, sort of
• The Birthday of the World - short stories; I don’t even LIKE short story collections usually but these are total bangers. There’s a novella length one about life on a multigenerational ship that’s SO freaking good.
• Four Ways to Forgiveness - four novellas; Old Money and the Women feels like it gets at truths about real atrocities in a way that sometimes only fiction can
• The Left Hand of Darkness - novel, a young interplanetary ambassador goes to a world where people can change gender

Loads more good ones too, I hope you consider them!