> In non-OOP languages, like JavaScript, functions can exist separately from objects. It was such a relief to no longer have to invent weird concepts (SomethingManager) just to contain the functions.

This is one of the things CLOS (Common Lisp Object System) got right: It's object-oriented but functions are not "owned" by classes; they're separate and first-class and generic and can dispatch on multiple arguments. In CLOS, classes are truly just user-defined types, and classes don't impede your ability to write functional code.