Artifacts in Modern have been overpowered since the start of the format. Even with multiple bannings targeting those archetypes, the iron machine continues to fight forward and remain a dominant force. Mox Opal and Krark-Clan Ironworks were removed from competitive play not too long ago and decks built around the power of artifacts still rose to the top. Even with these two cards removed, another artifact had to go to restore a forgotten shard of the metagame.
Arcum's Astrolabe was one of the most oppressive cards that most folks never noticed. It is humble in nature, as a small cantrip with some mana fixing is typically not a card that people grab the pitchforks against.
I wrote an article that called for its head months ago and explained the repressive nature that this card had on both Modern and Legacy. Entire aggressive archetypes were wiped out because the midrange and control decks could cast every . . .