Admittedly, its worth remembering that Brawl and Commander are literally different formats
All were doing is adding a commander which either weaponizes that storm count directly, like Thrasta, Tempests Roar and Aeve, Progenitor Ooze, or which accelerates the natural snowball of resources so we can eventually combo into a traditional storm kill: Gandalf the White, Karn, Legacy Reforged, Jhoira, Weatherlight Captain or Kinnan, Bonder Prodigy are great examples
You can get copies for just over $1 right now, which is an absolute steal given how good the card is
Then if you've done all four this turn, transform Avatar Aang
It is spread over three bodies, it is extremely hard to completely or efficiently answer, and it even provides ongoing value
According to EDHRec, Rampant Growth is the 8th most heavily played card in the entire format