Developers do this to keep fans and players interested and provide new content
A Stage 3 Pokmon with 310 health, you can use Psychic Embrace and play one energy from hand to immediately power up its Miracle Force attack, which deals 190 damage and cures Gardevoir of all special conditions
They have elements of token decks, but the tokens are used as sac fodder, not beat sticks
Standard also has two other creatures with this exact mana cost: Craterhoof Behemoth and Ghalta, Stampede Tyrant, which are much more proactive threats
This is often a great way to get a good distribution of trading cards to supplement your collection
One such card is Skill Drain, an ever-present in the game for many years due to its paralysing effect on many strategies, which remains a trump card for any deck that wont also be impeded by its all-encompassing negation effect