[extralego]

Your comment could give the impression this is drastically more simple to do than it is in reality. This is considered as something like the last frontier of VFX, and there still remains a lot of work to be done.

While you’re essentially correct, it is currently an overwhelmingly manual process. The amount of work and time necessary is substantial (some would say outrageous), and exponentially higher for certain types of shots. Many shots remain impossible or cost-defeating.