Typal decks are really popular, especially in Commander, so WotC is always releasing new typal cards to strengthen the existing archetypes or to create new ones entirely
Then, sacrificing a Food will create a 1/1 rat creature token, which will trigger Peregrin Took and generate an additional Food Token, creating a self-sustaining combo
Guzma is classified as a 2-Stars card in the Celestial Guardians set
Bronzor's steel and psychic typing grants it a unique role in battles, providing strong defensive capabilities against numerous types
While the payoff is big (a 9/9 is nothing to scoff at), getting there is cumbersome
You don't have to run it in an activated ability deck, but it's nice with things randomly like Avatar of Woe or Arcanis the Omnipotent in your colors