Energy counters are an unusual resource in Magic: The Gathering : Unlike mana, energy doesn't drain between turns or phases, and unlike Treasures and Gold they can't be stolen by opponents or used to fuel effects like affinity
Even if we're set back by board wipes, as long as we've done enough damage with our creatures, we can close out the game with an Exsanguinate or similar
That makes it a natural fit in Izzet or Dimir decks featuring cards like Assassin Initiate or Hookblade Veteran, where sneaky hits and tribal synergies go hand in hand
I can see this deck wanting to use all its mana, where Birds of Paradise is better, but I also think the advantage of getting a Food left over if the opponent kills Gilded Goose is pretty big, and I like that it does something proactive as the game goes long in making Food
Obviously exiling instead of sacrificing is a big deal, but Sothera requires everyone to have creatures in play for it to stick around