Animations are a big part of graphical fidelity. Games with lower-detail character models relied more on your mind to fill in the details as characters spoke or made facial expressions (I still remember an incredible scene in 2001's Anachronox where a character slowly smiles, conveyed with the motion of three vertices), but when you have a near-photorealistic rendering of a human face, the animation has to be up to standard. This is every bit a drain on art budgets as the modeling and textures.