He closes your lands down and benefits from them himself
Every reprint has repurposed art to match its respective story, and each deck tries to capture certain iconic events, characters, villains, etc
It also massively improves your first combat by giving your creatures first strike and untapping them, which allows for much safer and potent aggressive plays
This helps you in the long run, as when an opponent uses a spell or ability casts using mana from a Treasure, you put a +1/+1 counter on any creature and draw a card
Bygone Marvels is cool I suppose, but the decks not dying for a Regrowth effect, nor is explore that good at putting permanents in the graveyard for descend 8 to be consistently online
This excellent card-drawing artifact is one of the cheapest ways to turn a 1/1 body into two cards, and once your tokens are slightly bigger, you can turn them into more efficient threats