It is, although I’m not sure it’s complete. A list is one kind of monad, despite working like non-mutable linked lists would in any other language. They just happen to behave monadically, providing an obvious and legal interpretation of the monad functions. Going off of OP you might think monads are all Maybe.

I will say that the concept is overhyped in at this point, at least in Haskell, and there’s a lot of monads available that do what plain functional code could but worse.