FSR 3 works just like DLSS 3 which makes GPU generate fake frames and insert them between real frames. It does not use cpu for frame generation. Therefore it doesn't matter that CPU can't handle more than 30fps per second in certain area, because GPU will insert ai generated frames in between to increase fps. Normally when game is CPU bound, graphic card just generates the same amount of frames CPU can handle at the moment. With FSR, GPU can use this spare time to generate ai frames and insert them in between