I suspect this StoryGraph review of the book I just posted my own thoughts on captures what’s going on:
… a character who has agency but really doesn’t, which subverts the western idea of conflict that pivots around a main character always having to make the choice, do the thing, that runs the story. Here, no matter what Matt Kim does, the world affects him, does whatever it wants to him. Disappear him even. The ‘looseness’ of the story, as in, ‘I don’t get this book’, is imo holding up eastern cultural expectations of writing …