Why does Cyberpunk 2077 stutter in crowded areas on B550M?

I felt totally robbed of immersion while speeding through Night City; whenever I hit crowds, my FPS tanked from 80 to 30. I first tried enabling 'Ultimate Performance' in Windows Power Options, but while average FPS rose by 2, the jarring stutters remained. I then used the GamePP Resource Scheduler to lock the main process to Realtime priority. RTSS monitoring showed frame times converged from a chaotic 15-45ms to 12-17ms, and CPU load stabilized at 40-60% per GamePP, while HWMonitor showed temps at 65-72℃.