Imagine if someone said Killua will be the one to kill an arc villain and not Gon.
People will be like "cool stuff"
Sasuke will kill Juubito and not Naruto? Cool thing
Ichigo will not land final hit on Aizen, Urahara will! Makes sense.
Luffy will not kill Kaido, Zoro will lasd final blow? BLASPHEMY, LUFFY MC, HOW DARE U U TOXIC WANKER