Actually, I have found that using FSR2 when CPU limited to be very helpful. I have a 5900x paired with a RX 7900XTX so I am definitely CPU limited on my PC even though I’ve OC’d and undervolted my CPU to help out. Using FSR2 at the quality setting seems to offload work from my CPU to my GPU so I get the buttery smooth performance with minimal hit on visual quality. This also allows me to set my refresh rate to the full 120Hz of my Qled TV. While I can get 90-120fps at altitude flying over non-complex cities/scenery (@4k + HDR10) the fps will drop to 50fps at complex airports/cities and of course lower with FSLTL and other utilities running. These more taxing scenarios is where FSR2 really helps out as I can still get the smooth performance across the range of fps.
Now if I had a 7950x3D I’m sure it would plough through those more complex CPU intensive areas with ease and I wouldn’t have the large drop in fps! 