I would bet that at some point in the next few months a high-profile player will lose a high profile match due to a counterfeit card they had no idea about being spotted by a judge
Suddenly your Leyline Bindings are answering two permanents, your evoke Elementals become super-charged double triggering when they enter the battlefield, your Fable of the Mirror-Breaker is making double the Goblin tokens, and this isnt even considering the possibility of actually building around Elesh Norn in some sort of ETB heavy Soulherder or Ephemerate blink shell
The deck prices are almost always cheap too, so you can save even more money and get cheap sleeves if you need
In the early parts of last Standard I was really impressed with using Inscription of Ruin to just run people down with Mind Rots
But over time the loose phenomenon Ill call Commander creep led R&D to relent and furnish us with this little gem
This slows down your opponent aggression, buying more turns to get more attacks through and eventually win the game