As stated before, it is one of the most options per mana you can get from a card
While these packs only contain seven cards, much less than the other booster pack types, the crossover sets from Universes Beyond are smaller collections than traditional sets
Teferi, Time Raveler Locking people from casting things on other turns means they cannot cast more than one spell every go around, while you can use flash, instants, and stuff
Have Other Cards Received Errata to Make Them Books
The +1 ability is rather weak considering that it doesnt untap the land, though I would expect Wrenn couldnt start on more than two loyalty if it did untap the land
You can also mix it with things like Grip of Chaos to further randomize whats going on