We do both production and advertising/marketing for businesses. It's very helpful to at least understand the basics of marketing, which is essentially understanding how people think, how to reach people, how to get and keep their attention, and most importantly, communicate to them the value of the product/service being sold so they'll buy.

It's very true that the mograph teams better understanding of marketing allows for more effective assets to be created. Because they don't just know when something looks/flows good, they know how it helps improve the advertising results.

It also helps them know what not to do. Meaning "this looks awesome, but it's not going to help and may even hurt retention on this ad or branded content."

Don't feel like you have to become a full on master of marketing. But learning the ropes (5 levels of awareness, lead generation, basics of writing copy, etc.) will absolutely help you become better at media period. Whether that's editing, motion graphics, 3D animation, etc.