Genre tells you how a film was made, not what it's about. Two movies can both get filed under “drama” and have nothing in common. Meanwhile a Korean revenge thriller and a slow Iranian drama turn out to be after the same thing. Subplotly sorts films the second way — by what they're actually about, not what shelf they'd sit on.
Every film here has been read for what keeps coming up in it: the themes it returns to, the angle it takes, the films it belongs next to. Moral ambiguity holds 440 films where nobody comes out clean. Found family has 285 about people building the relatives they didn't get. Director pages work the same way — less a filmography, more a case for what ties the work together.