I attended a panel discussion at SIGGRAPH today that compared volumetric capture of people with computer synthesis of people. Both are ways of creating the appearance of a person in virtual reality or in a movie from a dynamic point of view.
The first uses an array of cameras to capture a real person from many different angles, so you can later move around a virtual camera to see that person from any chosen vantage point. The second is a computer graphic creation of a virtual person, which can be modified to look like anybody you wish — including people who don’t exist.
I am not sure it is fair to compare the two. It’s kind of like asking somebody to compare live action movies with animated movies. Each is good at a different thing.
I think it will be a long time, if ever, before synthetic humans are able to express all the emotional subtlety of a real person. On the other hand, volumetric capture is never going to let us create a really expressive Martian — or, for that matter, a really expressive Bugs Bunny.