Here are the four key reasons why card stock matters: Durability Card decks are meant to be used repeatedly, shuffled, passed around, and handled over time
It exiles any nonland permanent - that's a brilliant answer for things since you cannot save it by giving it indestructible in response like Flawless Maneuver or with recursion like Academy Ruins, and it's never coming back and sure to head out
SCG is selling Duel Deck copies at $4, and I think thats a perfectly natural price for the first few weeks of the sets release
One last Mythic Rare Eldrazi worth mentioning from Modern Horizons 3 is Kozilek, the Broken Reality
These decks represent two totally different philosophies
Instead of being just limited to creatures like Karmic Guide, this holy giant can get artifacts, enchantments, and even lands