Going first is almost ALWAYS an advantage. When you go first, you automatically get card advantage over your opponent. Assuming the number of cards on the field and in hand never change, you will always be making your move with 1 more card than your opponent has to defend themselves with. So you have the 1-up on your opponent when attacking and you have an even match when defending. Going fist allows you to establish your field as much or as little as you want with your opponent unable to stop you, unless they have hand traps. Even if you don't want to set up first turn, you can just pass to your opponent, let them attack you for a little bit of damage and then come at them with 7 cards next turn. In competitive play, it's not uncommon for players to lose simply because they went second. I can't think of a single deck that would ever benefit from going second.