Video game world models, renderers and cameras do not, with few exceptions, permit closeups. The geometry doesn't support it. Mirrors and optical effects are not the only thing a tracer can do that a rasterizer cannot. Geometry for days with a tracer.
The fact that nobody in the whole world has coded a CPU tracer of the kind I find interesting (besides me) is interesting, but not very. My hypotheses on it are left as an exercise for the reader.