3D models are a lot more complicated. You need to generate models, materials and textures separately. Need to split the model in separate parts that make sense

3D models are a lot more complicated. You need to generate models, materials and textures separately. Need to split the model in separate parts that make sense. Need to know where to use spline meshes, where to use instancing, how to group meshes and so on. Also which format to pick? Gltf is a good choice, I guess. But it's pretty limited compared to formats like .blend or .max. One of my favourite examples is a clockwork mechanism. Current 2D AIs always generate complete nonsense, because they have no idea how a clockwork mechanism works. A much more advanced model is required for something like that and it currently doesn't exist. A model like that is the bare minimum for 3D.