Giving somebody a free card attached to a two-mana 1/1 will, at best, let them make a land drop and pass not a high-impact play when youre already behind, and also far from guaranteed
It would require a massive and expensive printing effort on their part, not to mention the hiring of hundreds of people to sort through the submissions and mail millions upon millions of cards
Its a continuous removal engine for artifacts, and those tend to overperform
In the example above, Murderous RiderMurderous Rider is a creature thats a Zombie Knight, has lifelink, and when it dies it gets put on the bottom of its owners library
decks running cards like Return from the Different Dimension that bring back banished creatures
That's because it doesn't exist yet - and you need to create it, sharpish