In the Past, Everything was Cheaper Back then, a full set of CE/IE cards roughly cost $50, so people rebacked their gold-bordered cards so they could be played with their black-bordered cards
When a Siege is defeated, it is exiled, and its owner gets to play the reverse side (which could be a Creature, Artifact, or some other MTG card type) for free at Instant speed.
Ricardo Silva Efficiency is often key in Modern, and Inquisition of Kozilek fits in very well in such a format
Other decks that benefit from board wipes are those that accumulate value through non-creature means, like many enchantress or superfriends decks
8 Alela, Artful Provocateur One of the most synergistic commanders in Magic, everything Alela, Artful Provocateur does advances your board and can quickly take over a game