Why are turn transitions so slow in the late game of Civilization VII?

In the late game, clicking 'End Turn' resulted in a wait time that was absolutely maddening. I first tried enabling Dual-Channel Simulation mode in BIOS, but it didn't increase speed and caused frequent read/write errors. I then used the GamePP Resource Scheduler to raise memory read/write priority to Real-time and cleared all fragments. AIDA64 confirmed latency dropped from 92ns to 84ns, and turn speed improved by 20% per GamePP Timer, with HWInfo64 showing temps at 42-50℃.