What you mentioned ends up reducing the impact of RAM and CPU quite significantly, not increasing.
The reason why high end CPUs are generally tested in 1080p, is that almost all games at 4k would be GPU limited, not CPU. So you end up actually using less CPU, as it's spending more time just waiting for the gpu to finish drawing the frame before it gets called back to do work again.
Hardware Unboxed has tested and compared the performance of the Arrow Lake Core Ultra 9 285K and the Ryzen 7 9800X3D. Even after the performance enhancing updates and with the 200S Boost overclocking, the Core Ultra 9 285K is still no match for the Ryzen 7 9800X3D.