Even if you don't have it your opponent is probably scared of the potential for you to draw that Wastelands and end the game that way
That monster becomes that Monster Type
Heres the list so far: Major gains (30% or more): Minor gains (10-30%): Chalice of the Void, Noble Hierarch, Through the Breach, Doubling Season, Horizon Canopy, Engineered Explosives, Ancestral Vision, Mox Opal, Crucible of Worlds, Dark Confidant, Scapeshift, Brushland, Fulminator Mage, Ancient Stirrings, Lotus Bloom
For a time in the '90s, the Yu-Gi-Oh
You can also play lands from your graveyard with cards like Crucible of Worlds
For one, tons of unopened product changes hands multiple times before it ever gets opened, if it ever gets opened at all, leaving its final owner on the hook for the actions of all previous handlers