The Extended decks that Watchwolf would naturally go in have creatures that are just that little bit more outrageous, and the last few years have raised the bar to the point where Watchwolf no longer stands out
In an ideal situation, you would use Lethal Scheme to kill a huge threat, but sometimes the cards are more important
Theres so much spell fetching in Blue, and artifacts are one of the easiest things to generate quickly or cheat out for free
And Grave Titan merely makes Zombies, rather than being one
Let It Go Let It Go Lorcana Challenge foil promo
However, now that Vein Ripper has basically disappeared following the ban of Sorin, Imperious Bloodlord, Pioneer has become hospitable for Cauldron Familiar strategies again