These parts of the editing process can be very time consuming and complex, something not every “none-editor” always understand. They will often focus on how many different skills the editor knows, like if they also do some motion design or any VFX. If you look at a bigger production, like a TV show, the video editor is not expected to wear many different hats. For his employer to assume (without agreeing ahead of time) that he will also do the music, sound design, VFX, motion graphics, color correction, and grading, that would quickly become a toxic work situation.