That opponent is chosen as part of that additional cost
With flying, trample, and haste, it comes out swinging right away, and when it connects, you draw cards and pile on +1/+1 counters equal to the number of different permanent types in your graveyard, turning every sacrifice into fuel for both power and card advantage
Changes in card count over time While the number of cards continues to grow, Wizards has ensured its core competitive format Standard has a rotation of card legality, meaning it doesnt get too overwhelming
That's the real reason
Rather, environments act as glorified menus from which you select your next opponent, but this doesnt really hamper the experience because thanks to the random nature of a card game theres more than enough variety in gameplay
83/82, holds the honor as the first Secret Rare Pokmon card