Why does Dragon Age: The Veilguard drop to 35 FPS in large towns?

I felt extreme anxiety entering large towns as my FPS plummeted to 35, with GamePP showing memory usage at a dangerous 92-96%. I tried lowering texture quality to Low, but while it saved 1GB of RAM, the resulting blur and flickering were unacceptable for a modern game. I used GamePP Resource Scheduler to reduce memory recovery frequency to 12s and optimized the prefetch cache. RivaTuner then confirmed frame times converged to 16-22ms, while AIDA64 showed memory temperatures stable at 42-48℃ and fans at 1200-1400RPM.