Agreed on the CPU part unless you do 4K which then requires a good GPU and if the CPU is bottlenecking the GPU, you will get micro stutters because the CPU is not fast enough. Anything running at 1080p is going to depend more on the CPU. Going to 1440p will require some from both and 4K will primarily require a strong GPU and the CPU needs to be fast enough to keep up with its demands. My i9-10850K is still good enough to handle 4K but going from 30 to 60FPS requires at least a 3090 or 6900 XT.
MSFS 2020 is so main thread depended that you even can CPU bottle neck a 4090 in 4k.....especially close to the ground with a lot of live traffic infusion on complex 3rd party detailed airports in study level 3rd party airliner (which is the most fun). Doesn't matter the video card.....CPU has to calculate a lot, no matter what....