Your material has just a black color, that’s all. You can easily see this if you set a white background like so:
scene.background = new THREE.Color( 0xffffff );
This happens because the following line in your MTL file results in a black color. It represents the diffuse reflectivity and is mapped to MeshPhongMaterial.color.
Kd 0.0000 0.0000 0.0000