The most common reason. You just bought a new phone. You do not want to lose your Level 85 Mage with the full "Infernal Lord" set. Manually backing up the save file allows you to copy-paste your progress to a new device without relying solely on cloud saves (which can sometimes fail).
So, you ignored the advice, tried to edit your gold value in a hex editor, and now Darkrise crashes on launch. Here is the rescue protocol:
Search online for “Darkrise save file editor” or “unlimited gold save,” and you’ll find a murky underworld. Yes, you can download pre-modified saves with max stats or infinite currency. But beware: