The technology for cinematography to stage it didn't exist at the time.
Most skeptics will bring up the lighting of the photos that its to bright, shadows are to perfect, etc.
Creating that lighting would have been impossible because the lighting is parallel to the sun rays that's why the shadows where parallel to each other because the sun is 93 million miles away, to recreate that lighting you would need to build a wall of millions of lasers.
Skeptics will bring up photoshop but at the time of the moon landing, computers weren't greatly developed.
So basically the technology didn't exist to fake it.