Sui,

This discussion is something that led me away, for years, from Christianity (as it is presented in judeo-Christian churches, which I now refer to as Churchianity in order to emphasize that I do not find their theology standing). I couldn't stand how churches made statements like "Jesus saved us from our sins" (how so?) or "Jesus being sinless fulfilled the law" (how so?). The usual circles and gymnastics.

I pushed a lot of people away from Christianity by this discussion. I became pretty talented at it, really. I broke pastors, priests, reverends. I even met my now wife during that time and pulled her away from her church. I was so determined to break these questions wide open that I began learning Koine Greek.
And what I read didn't match the church slogans. And then a lot clicked. (And I read more and found more and reach out to like-minded outside away from the tax-free (i.e. state-approved) buildings more).

Here is why Christ died/how it did anything/why only his death would have accomplished what it did.

First: About God.
Think of God as willed objective truth. The only eternal being (which is different than 'everlasting'). God is truth itself, the spirit of truth. He tells us his name is Yahweh (meaning "I AM" or "I WILL BE"). Being truth, he is bound. Aren't we all bound to the truth? Yet the difference between us and God--what makes him holy (meaning "separate")--is that we can leave truth (to varying degrees but never entirely, depending on it ultimately, as all things rest on truth to some degree for their existence). Yet the truth cannot leave the truth. God cannot leave himself. That is what makes him separate.

Being eternal truth--the foundation and inevitable (or beginning and end)--leads to some calling him all-powerful. Yet he names an unforgiveable sin. (Not powerful enough to forgive it?) Remember that he is truth. Being truth, he is true in all things: righteousness, justice, love, knowledge. And he is true to himself. He cannot go against true justice, true love, true knowledge, etc. He cannot leave himself.

Onward to addressing our questions:

Why did Christ die?
"Till death do us part." When under a contract, you are bound until you or the other bound member dies.
If you make a contract with Truth (let's call it our "law" that will marry us to Truth as a Bride is to a Husband) and then you break that contract, the punishment for breaking that contract--that further binding you had made with Truth--is death (because you are leaving Truth, which all things rely on to exist). That is explicitly true if you write so in the contract.
So either the Husband (Yahweh) or the Bride (all under the law) must die.
The eternal cannot die. How then does eternal Truth save you? He cannot leave himself. He must be truly just, abide by the contract. He must be truly just, fulfill previous promises that he will save you. When does the Bride (even the unfaithful) become released from the Vow?
So the eternal becomes incarnate. A mortal body. The eternal, the Husband, dies. Hence the Vow is fulfilled (God remains true) and the Bride may live.

There were undoubtedly innocents that died under the imperfect practice of the law through the centuries. Their deaths didn't "fulfill" the law. Why? They were neither the Bride (the entirety of all of the Israelites) nor the Husband. (Half of the need to invent original sin is removed with this understanding. The other half of the need to invent it is removed with another topic: "Why do the descendants of Adam die?")

The death also accomplished more for the wider circle of all descendants of Adam (Whites), but this post is long.

Last note: kikes aren't our race, and just as kikes are "fellow Whites" in the media today, they were rewarded as "fellow Judeans" by the Romans for handing the Kingdom of Judah to the Romans. Christ called his sheep (Israelites) and told kikes (Canaanites, Edomites, Idumeans, etc.) that it is not meet to give to the dogs (them) that which is meant for the children (us).

Just as most women today are twisted into something repulsive, money is twisted, most education is twisted--so too is the practice and message that specifically calls them out.

I'm going to go get hot wings now. lol Good luck, bro.