In fact, according to EDHREC, its the sixth most-played green card in the format, appearing in almost 350,000 decks
I would actually argue that Armada Wurm is the more proactive of the two and that Centaur Healer is more of a sideboard card (though it depends substantially on the tenor of the metagame)
You can expect for it to gain 4 life and make 2 1/1s against any aggro deck which should be enough to stabilize the game and regain your footing
This casts your white removal spells, but also taps for blue, functioning as Tundras 5-6
The play booster packs replaced set and draft boosters and come alongside collector boosters with full set releases
These cards are still useful for building your decks, but are worthless on the marketplace