it is just the edgy furry ocs version of incarnations of immortality by piers anthony, whose devil character did this with a casino and was trying to fix god's inaction and hell's population issues and there was a casino

but don't read those books, piers anthony is trash

just has way more resemblance to those books than the good place, which doesn't have a "inspired by the xanth guy's other books" vibe at all but hazbin probably is a riff on incarnations' hell