> No matter how hard you spin the pencil, you're drawing a one-dimensional curve that has no area
The object doesn’t matter, using pencil as the example was what threw you off - it’s not about what the pencil “draws”. Consider a thin cylinder, or rectangular prism, or just a stick - if you spin it around, its endpoints trace out a circle whose diameter is the length of the stick. You can move and spin such an object in another way where the shape traced out by its endpoints has smaller area than that circle.
The object doesn’t matter, using pencil as the example was what threw you off - it’s not about what the pencil “draws”. Consider a thin cylinder, or rectangular prism, or just a stick - if you spin it around, its endpoints trace out a circle whose diameter is the length of the stick. You can move and spin such an object in another way where the shape traced out by its endpoints has smaller area than that circle.