What you two are proposing hasn’t been true for almost 2 decades. Most of the “graphics pipleline” operations are now implemented in hardware the GPU(s), not the CPU.
It’s why you have ray-tracers, shaders, etc., all implemented in the video card hardware and not the CPU.
In the case of the Arc 770LE, the hardware includes 4096 shading units, 256 texture mapping units, 128 ROPs, and 32 raytracing acceleration cores.
Those ROPs are a good example:
In computer graphics, the render output unit (ROP) or raster operations pipeline is a hardware component in modern graphics processing units (GPUs) and one of the final steps in the rendering process of modern graphics cardsSource: https://en.wikipedia.org/wiki/Render_output_unit#:~:text=In%20computer%20graphics%2C%20the%20render,process%20of%20modern%20graphics%20cards.
Rasterization hasn’t been CPU-based for a LOOOONG time, except in cheap shared-memory adapters that are just a bare-bones interface to the output displlay.
So what about the rest of the pipeline? Again, it’s mostly GPU, not CPU.
The model of the graphics pipeline is usually used in real-time rendering. Often, most of the pipeline steps are implemented in hardware, which allows for special optimizations. The term "pipeline" is used in a similar sense to the pipeline in processors: the individual steps of the pipeline run in parallel as long as any given step has what it needs.
Source: Graphics pipeline - Wikipedia
Gotta keep up with the times. It's why the Arc GPU contains more than 20.7 billion transistors. While the transistor count of the i9-13900 isn't known, the i9-12900k is a measly 2.95 billion transistors.