Why can we not reuse an alias template identifier with different template parameters?

Take the following example (https://godbolt.org/z/ouX3Vz):

template<typename T>
using A = T;

template<typename T, typename V>
using A = V; // Why is this not allowed?

template<typename T>
void B() {}

template<typename T, typename V>
void B() {} // Yet this is allowed?

int main() {
    A<int> hello = 10; // Allowed, T=int
    A<double> world = 20.0; // Allowed, T=double
    // A<int, int> bad = 20; // Not allowed, T=int, V=double?

    B<int>();
    B<int, int>();
}

We are allowed to have two function templates for B as the parameters differ, however, we are not allowed to have two alias templates for A despite differing parameters.

Is this an oversight in the standard or is there a rationale that I am missing? Are there any references to the standard describing this behavior?