She costs five mana, and just for a 3/3 body, under the curve, and she just has one ability
When Champions of Kamigawa came out, maybe a few players had a good time countering a huge spirit spell with it during the pre-release or in sealed pool games
But if you play Magic, you already know that stuff, so you can see the power and value of Garruk, Apex Predator
I suspect well be seeing lots of Torbran making appearances in Goblin decks
Second, because they can make any mana colour they can be great for getting cards on the board that you just dont have the lands to support, meaning a deck built around them doesnt need to worry if a card outside of its main colours is useful to have
The combination of all these elements makes this card incredibly meaningful