There is no single “whole” image when talking about a video game. It’s a combination of dynamic layers carefully interacting with each-other.
You can take any individual texture and make it look different/more realistic and it may work with some interaction but might end up breaking the game. Especially if hit boxes depend on the texture.
We may see ai remakes of video games at some point but it will require the ai to reprogram from scratch.
Now when we talk about movies and other linear media, i expect to see this technology relatively soon.