Why std::array does not contain an initializer-list constructor

In order to initialize a std::array with some values, you need to use this approach:

std::array<int,3> an_array3;

I am aware of the reason that we need two curly braces (one for std::array and the the other for the inner c-style array).

My question: Why, by standard, std::array does not contain an initializer-list constructor that directly initialize the inner c-style array? Is not more eyes-friendly to be initialized as:

std::array<int,3> an_array{3,4,5};