Goblin Ringleader is still a leader in his own right (are you sick of these puns yet?), letting you refill your hand with two to four rabble-rousers
Rakdos decks in Magic: The Gathering often have combos like this, and there are even new "one-turn-kill" strategies in Standard
Its definitively a mono-blue card unless youre doing weird stuff with Spy Kit
Fitting four-mana removal into your curve is normally awkward, but paying for Pile On partially (or entirely) by tapping creatures and tokens makes it incredibly flexible in the right builds
Against Affinity, Kataki, War's Wage can be just as good as Stony Silence, making it really hard for the opponent to execute their game plan
The spell's mana value remains unchanged, no matter what the total cost to cast it was