The best case with a clip-on lens is that image quality and light transmission don't get much worse than they were before. The only thing you can really achieve

The best case with a clip-on lens is that image quality and light transmission don't get much worse than they were before. The only thing you can really achieve with something like this is a different focal length (or focus distance range). Smartphones need more sensor area to compete on noise performance and dynamic range. No aftermarket accessory can help with that.