I think the main purpose is to learn how. Kind of like taking a fine arts class and learning how to paint a portrait.
Practically there could be any number of uses for a realistic human. The scenes in the Matrix with the multiple Neos. A stunt where you don't have or want to use a stuntman. Back filling a missing scene when an actor isn't available anymore. Making a young Harrison Ford or an older version of a young actor.
In video games graphics power is getting awfully close to being able to render realistic characters like this, though I'm sure there are optimization steps one would need to take before simply feeding something to Unreal or your game engine of choice.
On an individual level if you have a good human portrait, presented well, that's a pretty nice thing to have on one's demo reel.
Edit: I'm pretty sure the graphics power is there in modern consoles/PCs. It's up to the game's development and graphics team to make the animations look good.
I work in high end scanning for the movie industry. What "wardred" said is correct from my point of view: Getting familiar with the tools using a project that is "realistic" (pun intended) for both its content AND its application in TV, movie and games production (and very relevant, considering how much replacement is done in modern movies - not talking about Marvel alone but in general) and facing the challenges of that work and the tool(s) you use are fundamental stepping stones to build on.
No matter whether you include this experiment in your portfolio ("reel") or just honestly use it as your training grounds, having gone through it will make you a better CGI/VFX whatever (artist, tech, anything).
Even if you are only interested in learning about "realistic" renders/sculpts/meshes/rigs/layouts ... learning from various different sources in a variety of tools is important if you want to "make it" in the industry. Sure, you can always work as one of the millions of "free-lancers" (as in "we don't get paid we are in it for the fame"), but if you want to make a living from VFX, you need to know your gears. And you need to have failed miserably :-D
Marc Albrecht
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One reason to create such a realistic human portrait (or to explore realism in general with CG) is not just to learn the technical process of creating such a thing but the research one needs to do, the questions one needs to ask, and the general theory behind what makes a CG object look convincingly real.
The human face is probably one of the things we, as humans, are most discerning about. We can almost instinctively tell when something is off or "wrong" about a portrait. We've all seen many excellent "realistic" sculpts that somehow, in some way, just miss being fully convincing. In this course, Kent has done a lot of the groundwork for us as far as research and forming the right questions we need to be asking. Using photos of real people as examples he breaks down all the small things that make a person look convincingly present in the environment. Then he takes that into Blender and shows us how to reproduce those tiny details that really start to create true realism.
Through this course, we are not just given knowledge but a method of thinking and questioning that we can apply to any other project. What makes a tree look real? What makes a cat look real? How about a plate of food? We are less critical about non-human objects but our realistic CG humans will need to be interacting with objects at the same level of realism at some point.
Another thing I got out of the course was how to break down what seems to be a large and intimidating project into straightforward steps. While I have a good bit of experience sculpting human heads, the way Kent adapted the Loomis method to sculpting was incredibly helpful for me as far as troubleshooting problem areas. I have taken quite a bit from what I've learned in the course and applied it to my real media sculpts and also entirely different types of projects done in Blender.
This is some amazing responses, and indepth! thank you so so much for thouroughly answering this question!! I am motivated even more to move forward
