Parents will be like "eh, a pack of candies cost way way less"
Elesh Norn, Mother of Machines Hey, its that card that people are talking about banning
It can also be used to pay for additional costs that include generic mana.
While a Scorpion God deck would likely be constructed to contain numerous effects that put -1/-1 counters on creatures, in case one is ever in need, for three mana, The Scorpion God can put a -1/-1 counter on a creature at any time
Kari Zev also has some other good qualities, such as being a Human to slot into W/R Humans and having the ability to turn on Revolt each turn
That means the only time Silhana is a viable option for a card quality card is when your deck specifically scales with and utilizes creatures