In this Falls Wilds of Eldraine, Magic: The Gathering is returning to the plane of Eldraine, a world of monumental quests and a tenuous relationship between the various realms and the magical beings of the forests surrounding them
Batterskull Courser only gives one life per land made, usually just one per turn (although it does mitigate sac lands well as well as having great synergy with the shuffle!) and not always even that
If at least one target is still legal, the spell will resolve but will have no effect on any illegal targets.
In non-green decks, in particular, color-specific ramp like this doesnt come along very often
For Commanders that can afford it through cost reduction like Rowan, Scion of War, or Treasure generation like Prosper, Tome-Bound Crackle with power can end games in an instant