Every “hard” concepts I’ve seen in Haskell is immediately clear to me if explained in almost any other language. The hard part is Haskell, not the concept.
Usually I’m left wondering why whatever-it-is even has a name, it’s so simple and obvious and also not that special or useful seeming, it’d never have occurred to me to name it. I guess the people giving them names are coming at them from a very different perspective.
Exception: type classes. Those are nice and do need a name.
Haskell has a type system that lets these things be directly useful in ways they cannot be in many other languages.
You can't, in Java, declare anything like "class Foo<F<T> extends Functor<T>>", or use a similar generic annotation on a method: you can't have an unapplied type-level function as an argument to another type-level function.
These things get a name in Haskell because they can be directly used as useful abstractions in their own right. And perhaps because Haskell remains very close to PL research.