While this would already complicate box openings (since most packs will be losers, from a value perspective), the high bulk-rare rate could be redeemed if the rest of the slots were filled with really solid, high-end rares
Imagine how much more impactful they could be if you copied them
A simple Holo Rare from the Base Set in 1st Edition and good condition is worth infinitely more than a Hyper Rare or even a Mega Hyper Rare from a modern set
Traditionally, booster packs contain fifteen cards divided into four rarities, making them the most common way to purchase Magic: The Gathering cards
Timing rules still apply.) Mayhem represents an alternative cost that can be paid to cast a spell from your graveyard if you discarded the card with mayhem that turn
With this, you could guess what kinds of strategies they would try to use, or you could play a card forcing them to discard the top few cards of their deck if you found something you didn't want them to play