Here is the technical reason:
Released in 2005 for PC, Dynasty Warriors 4 Hyper was Koei’s ambitious port of the classic PS2 hack-and-slash. While the "Hyper" edition added graphical upgrades and a unique enemy aggression system, it also introduced a frustrating reality for PC gamers: dynasty warriors 4 hyper save file work
Introduction: The 20-Year-Old Grind