Comment by cubefox

Combining both ray tracing (including path tracing, which is a form of ray tracing) and rasterization is the most effective approach. The way it is currently done is that primary visibility is calculated using triangle rasterization, which produces perfectly sharp and noise free textures, and then the ray traced lighting (slightly blurry due to low sample count and denoising) is layered on top.

> However, full-scene ray tracing has essentially a fixed cost: the hardware needed depends primarily on the resolution and framerate, not the complexity of the scene.

That's also true for modern rasterization with virtual geometry. Virtual geometry keeps the number of rendered triangles roughly proportional to the screen resolution, not to the scene complexity. Moreover, virtual textures also keep the amount of texture detail in memory roughly proportional to the screen resolution.

The real advantage of modern ray tracing (ReSTIR path tracing) is that it is independent of the number of light sources in the scene.