There might be a good reason for this. Raster effects were already really good in newer games, and ray tracing could only improve on that high bar. It’s filling in details that are barely noticeable, but creap ever so slightly closer to photorealism.
Old games start from a low bar, so ray tracing has dramatic improvement.
Look at Pixar and other Disney CG stuff. Raytracing enhances stylized art just as much as photorealistic art. Something like Moana or Elemental is meaningfully enhanced by their work on water and glass transmission simulation.