The fact that you can block with this card then sacrifice it, and still get all this value, is what really pushes it over the top
Graveyard decks have always been a huge part of Magic , ever since the first Animate Dead was used to cheat out the first Lord of the Pit or Shivan Dragon
When I say cards that win the game I mean cards that have very good odds on winning the game, the few that exist which actually say win the game are pretty unplayable and not worth it
From the pre-game discussion about power levels or possible strategies to acclimatize everyone to each other's decks to making sure one's deck doesn't monopolize time at the table, these "rules" are in place to make sure everyone has a good time
They blend a unique package of discard, counters, and removal to cover all angles, all while having a relatively fast clock thanks to Deaths Shadow and Kroxa
Swords to Plowshares costs one mana, and this White instant exiles a target creature