Typically, a Limited deck wants to contain a certain threshold of creatures (depending on the strategy) because attacking for damage is the most common path to victory in the format
Tabletop Magic: The Gathering tournaments use a best-of-three system, in which players can use cards from a sideboard to adjust their deck between matches
Set: The Lord of the Rings: Tales of Middle-earth Art Series Rarity: Special
its likely that your Cube has some other card for 1B that will be upgraded more directly to Infernal Grasp, whereas Fateful Absence adds some depth to the relative dearth of two-mana white removal
We didnt get to talk about Diregraf Colossus, Rise from the Tides, From Under the Floorboards, Sin Prodder, Geier Reach Bandit, or a dozen other cards that have my brewers brain working on overload
Even if you don't use the Treasure token right away, just having that extra mana lets you cast spells ahead of your mana curve, and lets you take advantage of token and artifact synergies