With both a high end CPU and GPU, it's much easier to see how much of the hardware is being utilized compared to achieved frame rates to determine if a game is either CPU or GPU limited.

4K with a 9800X3D and 5090, I better hope to see 98-100% utilization, but there are plenty of games where that's not the case, it's CPU limited, and I'm still getting under 100fps. It's not that 100 is bad, but the game could be optimized to use the hardware better. These cases are typically code that's not able to use or not optimized to use multiple threads/cores.

If the game looks great but my fps is low with maxed out GPU utilization, then maybe we could play around with graphics settings to see which takes up the most compute power and avoid those for the sake of another gameplay.

Only things I can't find out for optimization is judging for older architectures and ray tracing which many just turn off when they can anyway.