How to enforce the C++ named requirement "Container"

I am trying to make a template container class and I want it to conform to the "Container" named requirement as best I can. I am looking at this cppreference link and at the bottom it says:

Other requirements
C (Container)
    DefaultConstructible
    CopyConstructible
    EqualityComparable
    Swappable
T (Type)
    CopyInsertable
    EqualityComparable
    Destructible

I want to add some static asserts in my code such that I never accidentally regress any functionality, and I am looking into adding it inside the class definition. Here is a minimal representation of my code:

#include <iostream>
#include <type_traits>

template <typename T>
class MyContainer {
    public:
        MyContainer() = default;

        static_assert(std::is_default_constructible<MyContainer>::value, "MyContainer is not default constructible!");
};

int main() {
    // instantiate the object so that static assert may be evaluated
    MyContainer<int> obj1;

    std::cout << "All checks passed." << std::endl;

    return 0;
}

However, when trying to compile this (at the moment using g++ 9.4), the compilation fails on the static assert.

Why is this failing?

Are static asserts even meant to be used this way? For example looking at my c++ standard library implementation of std::vector class, I can clearly see they use some static asserts like this (although not for checking that the "Container" requirements are satisfied) Also, any provided answer must be portable for all major compilers (g++, clang++ and msvc)