Please, how many FPS is your system doing?
Remember…for a simulator, 30 FPS is “normal”, because the simulator is simulating the systems of the aircraft.
MSFS is also known as a bad user of CPU. The optimization is still not good.
I just read about a guy who said that doing undervoltage at 3080 optimizes it.
Please, also check, in options of FS, if your system is locking the amount of FPS.