They have been graded as legendary artifacts, ensuring that their power levels are being protected within the tabletop trading card game
As soon as you have four Sagas in play, old Tom Bombadil becomes a big problem for your opponents to deal with, gaining hexproof and indestructible
Its common to Swords to Plowshares on Turn 1 (need a Plains), play an Island Turn 2, cast a cantrip to find your third land Turn 3, and in that line you wont even have UU as an option to leave up until Turn 4, but you could cast Veto on Turn 2 or 3 along the way
This punishes players who want to loop creatures in and out of the bin, and rewards you with some fantastic blockers for your trouble
If you dont spend any mana to sac it for a card, you still fetch two lands when it croaks