What's inside matters. We have so many sayings and metaphors reflecting this idea. "Don't judge a book by it's cover" etc.
A cake can have the prettiest, best-looking icing in the world, but if it doesn't taste good, nobody will eat it, and no one will remember. Don't allocate the majority of your time making pretty icing, instead, bake a damn good cake.
We remember what's inside, the frills are literally just the icing on top.