Stop peddling meaningless hype. Current 3D rendering technology is lightyears ahead[1] of these AI toys and you can trivially parametrize it. Many games already do. So if you want to generate people, you already can do that while having full control, instead of some glitchy sliders.
Something genuinely useful might, perhaps, be achieved by applying GANs to parameters of those 3D models to allow easier customization, but I haven't seen any work in that direction.