Why use private static in PHP methods?

Question

PHP

Good afternoon!
As far as I understand, the static methods of a class allow themselves to be used without creating an instance of this class. Those. in fact, we can use these methods just like ordinary "functions".
Something like:
MyClass::stati_method()
But often I see that private static methods are used. Why make them private, because then the above example will not work. Help me understand this nuance

Answer 1

It will work within the class MyClass.

Answer 2

Most often, I observe this behavior in the implementation of the singleton pattern https://refactoring.guru/ru/design-patterns/single...