Why is the question of the origin of proteins at the core of most materialistic theories of the origin of life?

This question is important, since the appearance of proteins served the origin of life on our planet. Although many other factors and substances, such as water, carbon, hydrogen and others, are also very important, proteins have a complex structure, which is not clear how it appeared. But scientists have already come to a clue. The thing is, our planet has had billions of years of trying. In the end, this and the presence of all the necessary chemical elements make the planet doomed to the emergence of life. And proteins are not so difficult at the right time.