T'Challa: We can still heal you...
Erik Killmonger: Why, so you can lock me up? Nah. Just bury me in the ocean with my ancestors who jumped from ships, 'cause they knew death was better than bondage.
T'Challa: What do you want?
Erik Killmonger: I want the throne.
T'Challa: My suit is good.
Shuri: Old tech. Functional, but old. "People are shooting at me - wait, let me put my helmet on!"
Shuri: It's like riding a hover-bike.
Everett K. Ross: You have hover-bikes?
Okoye: Wakanda forever.
Erik Killmonger: Hey auntie.
M'Baku: If you say one more word, I'll feed you to my children! I'm kidding. We're vegetarians.
T'Challa: Wakanda will no longer watch from the shadows. We can not. We must not. We will work to be an example of how we, as brothers and sisters on this earth, should treat each other. Now, more than ever, the illusions of division threaten our very existence. We all know the truth: more connects us than separates us. But in times of crisis the wise build bridges, while the foolish build barriers. We must find a way to look after one another, as if we were one single tribe.
Everett K. Ross: I have seen gods fly. I have seen men build weapons that I couldn't even imagine. I have seen aliens drop from the sky. But I have never seen anything like this. How much more are you hiding?
King T'Chaka: The world is changing. Soon there will only be the conquered and the conquerors. You are a good man, with a good heart. And it's hard for a good man to be a king.
N'Jobu: No tears for me, son?
Erik Killmonger: People die every day. That's just part of life around here.
Shuri: This corset is really uncomfortable, so can we all just wrap it up and go home?
W'Kabi: You would kill me, my love?
Okoye: For Wakanda? Without question.
T'Challa: I am not ready, baba.
King T'Chaka: Have you not spent so many years by my side, watching and learning, preparing for this day?
T'Challa: That is not what I meant. I am not ready to be without you.
King T'Chaka: A man who has not prepared his children for his own death has failed as a father.
Everett K. Ross: Does she speak English?
Okoye: When she wants to.
Nakia: You cannot let your father's actions define your life. You get to decide what kind of king you want to be.
Shuri: Don't scare me like that, coloniser.
T'Challa: I never yielded! And as you can see, I am not dead! The challenge continues.
Shuri: Another broken white boy to fix.
Shuri: Did he freeze?
Okoye: Like an antelope in headlights.
Answer: Zuri feels guilty for his role in the death of Killmonger's father, which is why he tells Killmonger to kill him instead of T'Challa. While Zuri himself probably doesn't actually want to die, I don't think he wants Killmonger dead either, which is why he wouldn't kill him. Also, as a royal advisor, it would probably be looked down upon by the other tribes if he violated the rules of the ritual combat. After all, one combatant has to defeat the other in order to rightfully claim the throne.
Phaneron ★
Zuri may not want Killmonger to die, but he knew that the duel would only end once one of the contestants would either surrender or die, meaning Killmonger would stil win or kill T'Challa. It seems a rather low price to be looked down upon or fired if it means your country doesn't go to war. At least, that would be a small price to pay for keeping the peace.