Try use 3080ti instead. (your title intrigue me).
Well, try show the CPU and GPU benchmarck (like MSI afterburner). See your GPU hits 99% or not. Also see your CPU hits 100% or not.
GPU not hit 99% means something block it to use all its power (unless you limit it with undervolt or low settings or vsync). But if you just use default settings and max out that GTA V with 2K resolution, should 99%.
all CPU core 100% then CPU blocks your GPU.
What we see normal (you can check on youtube benchmark various games), GPU 99% and CPU not 100% (depends on game and how game use all cores you have)
MSI B550 Pro-VDH - MSI 6600XT - Ryzen 5600G