Your hard drive crashes, or you upgrade to a new gaming rig. Steam Cloud is helpful, but it is not infallible. Many users report losing 60+ hour Raid Mode progress due to sync errors. A community-sourced save is the only way back.
"No. This game is seven years old. Many players have beaten it legitimately multiple times. Using a save file to access NG+ or Raid Mode endgame is no different than using a Game Genie in the 90s." Resident Evil Revelations 2 Pc Save Game 100 Complete
For players who have switched PCs, suffered a corrupted hard drive, or simply want to jump straight into the endgame content without 80+ hours of grinding, a 100% complete save file is the holy grail. Your hard drive crashes, or you upgrade to a new gaming rig