Quote from Wildfire393 »Explore works best, IMO, because every* deck is approximately 30-40% land, so you've always got a solid chance of hitting the card despite deck composition. Lands are also frequently worth less than other cards, so it makes the card advantage mode on it less oppressive.
*: There's obvious exceptions like Oops all Spells, Manaless Dredge, Belcher, 10-land Stompy, etc, but none of those decks are even going to look at these cards so that's irrelevant.
What you're talking about really only applies to Modern and Legacy.
There could easily be Standard environments where other card types could make up a similarly high percentage of a deck.
This is almost always true of Creatures, and it could easily be true of Artifacts, as well.
Enchantments, Instants, and Sorceries are a bit trickier, but still possible.
Planeswalkers are probably too "rare" for that to be worthwhile.