Grixis Affinity depends on cheap artifacts like Ichor Wellspring, affinity lands (Seat of the Synod, Vault of Whispers, Mistvault Bridge, Drossforge Bridge), and Blood Fountain to discount Myr Enforcer and Refurbished Familiar, so Dust to Dust exiling two artifacts at once can meaningfully set back their curve and metalcraft for Galvanic Blast. Standard Bearer redirects their removal and Galvanic Blast away from our real threats. We trim Phyrexian Walker and Ornithopter since they trade poorly with Myr Enforcer and flying Refurbished Familiar/Utrom Monitor. Note their artifact lands like Drossforge Bridge and Mistvault Bridge are indestructible, so Dust to Dust (exile, not destroy) is the correct way to interact with them if needed, though spending it on their creatures or Ichor Wellspring is usually better value.