Dimir Midrange leans on removal like Requiting Hex and Bitter Triumph plus the powerful planeswalker Kaito, Bane of Nightmares, so Duress proactively strips their interaction or disruption before it can be deployed. Bitter Triumph answers Kaito or any other creature/planeswalker threat they stick. Ingris Stingerquill and some copies of Flamecache Gecko are cut since they're vulnerable to the opponent's efficient removal suite and don't close games fast enough against a grindy deck with card advantage like Enduring Curiosity. Keep pressure on while disrupting their hand.