Think of it like you put in the effort to curate a collection of recipes that work well together, and that curation is what’s copyrightable.
I don’t know what will happen with the law, and if APIs like this will be deemed a “curation”, but it makes a lot more sense to me from that perspective.
Ex.
Anyone can have a `Math.remainder` function, but the curation of an entire `Math` library might be copyrightable, since the effort was in collecting all of the correct things that work well together, even if they aren’t individually copyrightable.
A mega-recipe containing other recipes would be like making a `Math.AddAndThenMultiply`, which even if someone else had created the Add and Multiply methods, you aren’t stealing their API curation of methods, you’re just combining logic/algorithms (ingredients) from multiple methods (recipes) into a bigger method (mega-recipe).