Forum:What's with double drawers?

What makes them so special in the TCG that most of them are all of high rarity? Like Allure of Darkness and Rare Value. I understand when such is done for cards as Mirror Force and Honest cause of their power, but seriously, draw 2 cards? If you think of it, and personally, just drawing 2 cards isn't that powerful or useful. Specially when it can deck you out.