The TLDR version is this: build a near-infinite engine to gain excellent card draw and play increasingly useful cards on early turns
Credit: Wizards of the Coast Rukarumel, Biologist FromTheShire: Rukarumel is kind of addressing a problem that people sometimes think they have that I don't think is actually a problem
Epic Rarity : Positioned between Legendary and the coveted Enchanted rarity, "Epic" cards are designed to be a more frequent exciting pull than Enchanted cards
This version of Hook comes down quickly at just one ink and can target down any vulnerable cards your opponents play early in the game
Baleful Strix Grima, Saruman's Footman Dimir Infiltrator Master of Death Lazav, Dimir Mastermind Halo Forager Obsessive Stitcher Araumi of the Dead Tide Etrata, the Silencer Tomebound Lich Cavern Harpy Dimir Guildmange Tidehollow Strix Oonas Gatewarden Aven Hearstabber Big Monsters Dimir doesn't have as many large creatures as other colors, but it does have a few
Because Set Boosters sold better, they chose them