And I'd say the average React or Java developer these days understands both pretty well. It's the default way to render a list of things in React. Java streams

And I'd say the average React or Java developer these days understands both pretty well. It's the default way to render a list of things in React. Java streams are also adopted quite well in my experience. I wouldn't say one is more difficult than the other. IMO `map` is a really bad example for the point that OP is trying to make, since it's almost everywhere these days. FlatMap might be a better example, but people call `.then` on Promises all the time. I think it might just be familiarity at this point. Generally, programming has sort of become more `small f` functional. I'd call purely functional languages like Haskell Capital F Functional, which are still quite obscure.