If you are developing a AAA title with "hyper-realistic graphics" or a more artistic, cinematic game you can use raytracing to achieve effects which are otherwise 'faked', give you unique effects, or just to get more dynamic lights in scenes.

Indies and less realistic or more "casual" games may not bother with it, just as many of them don't bother with things like parallax mapping and some don't even bother to use textures at all. The features are there and easy to use but developers opt in and out of the different rendering options based on their artistic styling.