Are Basic Shapes in unreal Intended to be used as game geometry or do they have to be replaced with meshes?

When you can create basic shapes and meshes in unreal engine like boxes, cylinders, spheres and cones, are those meshes meant to be only for guideline purposes for the games? On my old computer, these volumes caused more processing draw than using meshes.

If I am building an apartment building with basic cubical rooms, would I have to replace the volumes used as walls and floors with actual meshes at the end?