Because card designs usually treat sacrificing as a cost rather than a payoff in itself, they are far less likely to include additional limitations on how often an ability can be used, and youre more likely to get valuable resources (mana, cards, other permanents) out of the exchange
[-7]: You get an emblem with "At the beginning of your end step, put X 2/2 black Zombie creature tokens onto the battlefield, where X is two plus the number of Zombies you control." |3| See more Add To Wishlist Restock Notice Gatherer & Rulings (opens in new tab) NM EX VG G $4.49 Out of stock
Its unsurprising to see that this card managed to positively explode at auction
Similarly, if all of the attacking player's other opponents leave the game before Suppressor Skyguard's last ability resolves, the condition will no longer be true when the ability tries to resolve, the ability won't resolve, and damage won't be prevented