Ray tracing can turn good modeling
into a beautiful picture. However, it is extremely
computationally intensive, with somewhat unpredictable
compute time, which makes it inappropriate for real time
rendering of scenes.
It use to be that ray tracing was the only way to get
a photorealistic scene. As the simulation industry grew,
it began to demand near-real time 3D rendered scenes,
so faster methods than ray tracing had to be created.
It started with constant shading which doesn't look real
at all, but is almost good enough.
Then Gouraud shading, Phong shading, and texture mapping were developed, which while not quite as good as ray tracing,
look real enough, and
are reasonably fast, and can be done in real time
with a bit of hardware assist.
Although these methods still don't look as good as ray tracing, they make a good complement. Most advanced solid modeling
programs support one or more of these fast methods
in addition to ray tracing.