I work in deep learning research. In my opinion, pose estimation with one human centered in a frame is nowhere near the level of difficulty of constructing an accurate model of a complex a scene with multiple people and moving objects of various sizes. For instance, it wouldn't be so hard to detect that there is a train in this video, but to do upscaling correctly, you need a 3D model of this specific train. Yes, there exist deep learning models that try to do 3D reconstruction, and so far, I haven't seen anything that works robustly. Combining this information with an upscaling model is another challenge. It's not as easy as just plugging components together.