They add extra utility and allow players to "cheat" on their land counts and play a higher density of spells
It's not just huge, it doesn't just not have an upkeep and not have a restriction on untapping
Sure, the front side is a nonbo with Niv, but it's great with Yorion, Sky Nomad, which is often used as a companion, and Niv or Omnath can flip the battle in just one attack
Legendary Creature - Wizard Zack Fair Zack Fair enters with a +1/+1 counter on it
Ive also noticed it really brings down the mood of casual playgroups, as having your card effects simultaneously stolen from you and used against you doesnt feel especially good
Ertai Resurrected Four mana is a lot of mana to keep up at any given time, and giving opponents extra cards isnt something you want to be doing, group hug decks excepted