It takes a long time to get good at all the different elements of video production and it takes even longer to get good and fast at the same time... You have scripting, location, props, talent, food, lighting, sound, movement, blocking, editing, vfx and color and then delivery of some pretty large file formats that compared to photos could take days to upload unless hard drives or gigabit connections are used. Add in technology like live cellular bonded streaming, motion control camera matching, A.I. creation and repair and it's no wonder why most production houses & studios have teams of people all specializing in just one to a few areas.