Update 2021-10-24: I just discovered the rokoko mocap suit which puts the bill at $4000 for digital actors: https://www.rokoko.com/ Update 2021-12-15: A nice recap on the unreal 5 technology showcased for the Matrix: https://www.youtube.com/watch?v=gry36cT3TdI
It seems that the future of cinema will go through a steep decrease of production costs due to technical innovations.
The first example of this is the Mandalorian series which is no longer using physical sets: instead what they do is they create all the locations digitally and they render everything in a massive screen behind the actors. And this is not only cheaper but also enables changes in real time to the elements, to the lights, … You can see the final results immediately, instead of waiting a few days to get the final shot in postproduction.
A more extreme example is the short film Irradiation. In this case, the shooting is done with actors wearing MOCAP suits and the camera is a tablet that is displaying directly the final rersult with the locations and the actors characterization (clothes, physical attributes, …).
Recent advances in ML let you capture the pose and face expression of a person directly from a 2D video with a single camera. This opens up the possibility of shooting a video with your phone and having the final result directly rendered on it. It would be an extremely cheaper version of what we see for the movie irradiation (without the mocap suits or the expensive equipment)
And finally what we are also seeing is that the creation tools are also improving and getting cheaper: Unreal release a tool called metahuman that lets you create human figures in minutes. VR is bringing immersive tools to create 3D locations. Those VR tools are already being used for the series The mandalorian.
Sources:
Filming the entire movie with motion capture and real time rendering in Unreal Engine
The Dome (where you project the Unreal Engine render in a giant screen). This is used by the Mandalorian series.
Unreal Engine rendering:
AI pose estimation from simple 2D video.
Easy tools for creation model:
Easy tools for creation model based on VR