For me, this card is a hit because it can be very good and its not just generically powerful
One big advantage Nyxbloom Ancient has over similar effects like Zendikar Resurgent -- aside from making 100% more mana, that is -- is that it's a creature, which means it's much easier to cheat on its whopping 7cmc
This card is famous for its dynamic battle scene against Charizard, acting as one half of a breathtaking diptych
Luckily, since the Sun & Moon era was so recent, you should be able to find most of these cards in near-mint (NM) or lightly played (LP) conditions
It has a large HP pool for survivability, it has a powerful Thunder Fang attack, which deals 80 points of damage with no drawbacks, and it inflicts the Paralyzed status effect on one of the opponent's active Pokemon
To make it easier to jump in with friends, most sets get preconstructed Commander Decks built around a specific theme or playstyle