yugioh machine cards The Best Decks In Yu-Gi-Oh! Machine Duplication | Card Details

Not to mention that playing multiple spells a turn is a good way to fill your graveyard

An effect that instructs a player to cast a copy of an object (and not just copy a spell) follows the rules for casting spells, except that the copy is created in the same zone the object is in and then cast while another spell or ability is resolving

You spend time and resources digging into a bank and draining its loot (tapping the Bankbuster and spending mana to get cards over a few turns)

If youre 2/3 for three hangs around a turn or two, you would likely have won without it, as your opponent wouldnt be putting much pressure on you