McDonald's has had similar problems with other campaigns in the past, including a collaboration with the "Chiikawa" manga series that was also targeted by online resales
Iconic Cards: Splinter Twin, Senseis Divining Top, Copy Cat, Living End, Primeval Titan, Grinding Station Popular Decks: Oops, All Spells!, Twin, Grinding Station, Mill, Belcher, Storm 6 Ramp Ramp decks want to generate a ton of mana to cast really powerful cards
On top of that, you can absolutely pay 0 for x and wipe all artifacts with a mana value of zero, which seems ever more relevant with this years increase in Clue, Food, Map and Treasure tokens
Art and border play heavily into wow factor as well