For one thing, we can get those Spirits at instant speed, whenever we need them
Right now, the average value of the original printings of the set's 121 foils is $17.60 (the median value isn't quite as high but is still impressive, at $11), which means if these prices hold once the set is released next week (which they certainly won't), just the 24 foils you open in a box would add $423 to the box's expected value
Planeswalkers have appeared in precons before, but theyre usually capped at one per deck
Even for Secret Lair, this collection of drops is a departure from an already chaotic norm for Magic
Still, if you want a bounce spell, you could do much worse than having the other three abilities attached to it, especially if your deck cares about the top deck manipulation from a repeatable Brainstorm
It can go either way