While we do have cards like Glorybringer, Atsushi and Moonveil Regent to help enable it, they are also just solid midrange cards in their own right
They're made as tribute material and the more easily you generate these tokens, the easier it is you play the big eldrazi spells
That means that while Charizard, Pikachu, and Mewtwo are exclusive to their Genetic Apex variants, Mew, Palkia, and Dialga can be acquired by opening Mythical Island and Space-Time Smackdown packs, respectively
Six mana for the current stats is simply too much for a playable card
(If this creature isn't monstrous, put ten +1/+1 counters on it and it becomes monstrous.) When Grim Giganotosaurus becomes monstrous, destroy all artifacts and creatures other than Grim Giganotosaurus