Exactly, planning the visuals early prevents wasted work later. Most successful games start with solid concept work that defines characters, environments and overall mood before any 3D production begins. It's way easier to change a drawing than rebuild a finished model. Professional concept artists help nail down the style and create a visual guide for the whole team to follow. You can see examples and services at https://kevurugames.com/game-art/concept-art/ where they develop everything from character designs to environment concepts. Helps keep the art consistent throughout development and gives 3D artists clear references to work from instead of guessing what things should look like