Why does null exist in .NET?

Question

Why can values be null in .NET? Is this superior to having a guarantee where everything would have a value and nothing call be null?

Anyone knows what each of these

Answer 1

To denote the nothingness concept, since 0 is not the right fit.

Now you can give any value type a Null value by defining a nullable type.

I think we can't have a value always for the variable because at first we have to default it to some value, and here comes the question why a specific value takes advantage over the others.