While you have no cards in your hand, face-up "Infernity" monsters you control gain 400 ATK and DEF. You can send this face-up card from the field to the Graveyard to send all cards from your hand to the Graveyard.
Just straight "discard your hand" has never been good. There's a reason cards like The Cheerful Coffin have seen very little play, if any. Card Destruction is powerful because, in addition to putting things you want in your Graveyard in your Graveyard, it also gives you cards to replace those you lost.
pretty useless card why would you ever discard your entire hand to graveyard