Sometimes in the late game drawing your ramp spell is pretty awful, and this becomes a 4-mana Sorcery that Proliferates twice in that situation, and thats often going to have a significant impact on the board
The Charizard card became one of two chase cards in the special set Champion's Path and the Full Art Marnie will be a promo in the Marnie Tournament Premium Collection
They did the same with Antique Old Amber and Aerodactyl ex, so it's not just Unfezant
Sorceries are one of the least played card types in cube, their number vary a lot from archetype to archetype too
Plus, players might likely be more than interested in replaying its ETB effect over and over than anything else
Among the various systems the game introduces, Crafting Pack Points (CPP) stand out as a central currency for building your collection in a strategic way