The Tyranny of Time by Joe Zadeh, which is about time, natural time, the standardization of time, the impacts of clock-keeping, and late capitalism/environmental disaster. (Naturally my primary takeaway was about whether the spiritual realm in Bleach was round like a planet and how the sun influenced their architecture.)
Because of Palestine by N.A.Mansour, which is about being a scholar of history from Palestine, working in the U.S., and what stories the archive does and does not tell.
How to Tell a Trauma Story by Bethany Marcel, which is SUBLIME and funny and horrible and wonderful. She talks through a lot of things I think about a lot when writing Sam and Dean, so that's an added bonus on top of it being immaculate to begin with.
The Reality Behind the Dream of Total Freedom by Sebastian Junger, which is about a topic I think about endlessly but often find difficult to articulate due to its capaciousness, the way the ideas it interrogates are so baked into assumed norms. It made me really want to read his full book. This one also has big SPN vibes.