Of course, the biggest upside of Zirda, the Dawnwaker is that its cost reduction applies to all permanents (see: the Basalt Monolith / Grim Monolith combos for Commander), and some artifact-based decks come very close to accidentally meeting Zirda, the Dawnwaker's companion restriction (for example, Modern Urza decks often only have Uro, Titan of Nature's Wrath as a permanent without an activated ability), so the unique wording on Zirda might open up new possibilities, compared to Biomancer's Familiar and Training Grounds, that will take time to explore
You dont need lands if you intend on swinging for lethal damage so you may as well take away everyones mana to reduce the chances that something goes wrong
while ink can be pricey, it often goes a long way
Most decks wouldn't be able to do anything at all without lands to support them, and yet, most Magic players forget about lands as perhaps the least dynamic card type in the game
Not only can this card wipe graveyards, but it can also gain life and blow up artifacts and enchantments
