Board Thread:Questions and Answers/@comment-32498184-20171001095404/@comment-4565782-20171010015746

Because a mixer doesn't deal with the technicalities of video production?

There's a lot more that goes into processing a video than you think. It's not as simple as just adding the sound file to the video file and saving it into a video container.

Also I'm getting the feeling you have no idea what a mixer does. What they do is fix up the audio, add effects, and overall process the vocals so they sound good. The whole process it a lot more detailed than that but that's the overall gist. Their job isn't to combine all the files together despite what their title might seem like to you.