Why does Cities: Skylines II freeze with 100k residents?

As my city grew past 100,000 residents, the screen would freeze instantly, which is absolutely lethal in a real-time simulation. I tried increasing virtual memory to 64GB, but this actually worsened disk read/write conflicts and increased the frame drops. I enabled GamePP NVMe Queue Depth Configuration to optimize the read queue depth to 1024 and adjusted the indexing strategy. CrystalDiskMark showed 4K reads improved to 55-62 MB/s, and AIDA64 confirmed stable temps at 40-46℃.