Alice Madness Returns
A 2011 game that has better hair physics than a 2020 game?... :v
Well, that game may have had cool hair physics...for the
one character model that was available to players in the game...within the linear, level-based approach of the game...and a physics system that was
scripted, not randomized or emergent. That's a significant amount of processing overhead compared to something like TW3 or CP2077.
Add in an engine that allows for multiple hairstyles, colors, textures, interchangeable gear slots, a procedural, open-world design, potentially hundreds of characters on screen...then trying to ensure that the hair physics react believably to the amount of moisture that's supposed to be in the air. That might start to take up just a few too many processing cycles at times.
I'd imagine hair will represent a.) still, b.) breezy, c.) windy, and d.) wet. Long hair might be too difficult to get working right with all the possible customization combos. I'm not saying that it's not possible or that it wouldn't be cool -- it's just a tall order for everything else the game needs to accomplish, is all. I would imagine a few hairstyles might be longer (some clothing options, too), but I think they might be necessarily a bit stiff because of technical limitations.
Dragon's Dogma is a good analog for the challenges of getting "long" hair / clothing / robes / capes working well. Physics skeletons become much more complex the more moving "joints" there are, and the number of possible physics influences that could act upon each joint exponentially increases the calculations needed to model the movement instant to instant. Thus, most games that offer lots of customization have certain parts that are physics modeled, and others that are statically animated. It's one thing to soak up some processor cycles to animate a braid of hair, shirt-tails, or a scarf. It's a totally different beast to animate indivual locks of hair that may need to interact with the wind, the character model, direction of motion, and weapon on the player's back frame-by-frame. That's a
lot of processing. (As in, "Bye-bye, framerate!")