You can reanimate an artifact or creature straight from an opponents graveyard, forcing them to mill that many cards afterward
Sometimes, Card Advantage can be more important than Card Draw, especially in decks with lower card quality
Hall of Confusion Plane: Ushval Players play with the bottom of their deck face-up
Having a 1/2 flyer is cool and there is a mildly useful ability
However, in competitive formats like Modern or Legacy, there are more efficient and powerful options like Ral, Storm Conduit or Teferi, Time Raveler that may overshadow Ral, Crackling Wit, making it less likely to see play in those environments
@Quuador and @mannynotfound covered it well by linking to the last Imgur album I put together as well as hitting some examples I dont have