Soldato
Doing a good approximation of a higher quality ray tracer though using path tracing and the denoiser - Quake 2 is using it for more than just reflections - all lights and global illuminations use it as well as having caustic approximation though scattered/indirect light bounces seem to be highly constrained compared to a ray tracer - it doesn't seem particularly troubled by scene complexity or geometry I've been messing about with some custom maps and increasing scene complexity significantly beyond the stock maps has less than 1% performance impact.
Thats the thing, Path tracing is more computationally expensive and more physically realistic compared to ray tracing.
Path tracing allows caustics and multiple bounces, along with diffuse scattering etc.