You can win a Pokmon TCG battle by taking all of your six prize cards by knocking out your opponents Pokmon (different Pokmon equate to different numbers of prize cards), leaving your opponent with no Pokmon in-play, or running their deck down so that they have no cards left to draw
I like this card a lot, as pushed as it feels
Its a way for decks to consistently find certain cards, most often combo decks, which means that the cheaper and more efficiently a card can perform these actions, the stronger it is as a tutor
Proliferate will add ability counters too, and while that wont normally make a difference, you could use those extra counters for other effects, such as activating Tekuthals ability to add an indestructible counter on itself
That format had weak removal and was all about going big with a single creature via Heroic, Monstrosity, and Bestow, so that made sense