It works on almost any platform, be it web, mobile, desktop or server via Fable, Xamarin or .NET Core.
It can work as an object-oriented language as well, which makes it easier to interface with C# code, but the documentation makes it very clear that functional is the way to go for F#.
For UIs there are libraries like Fabulous and Elmish, that provide a very similar programming model as Elm does.
You can even share code between all your target platforms:
It was a bit of a slog, but there are some wonderful books out there. I don't think we should discount the amount of pedagological resources that are available in the language. My favorite is the "First Principles" book.
As a side effect, I found that once I had learned most of Haskell (minus some of the language extensions aimed at type level programming). You pretty much won't find anything in any other typed language that will surprise you.
For people from dynamically typed or static OO background, being able to write functional code with records and sum types alone is a huge quality of life improvement. They should be able to get there with the least amount of effort. Haskell however demands far too much understanding and effort before it can be confidently used in a commercial setting. That excludes mainstream programmers who could otherwise most benefit from the paradigm.
I'm struggling to justify spending more time on picking up Haskell myself as I can't see clearly what's at the end of that tunnel.
It is only recently that I've started getting comfortable with concepts cogently explained in this post, so to me it is quite valuable.
As an aside, I think OCaml/Reason/Elm should become the de-facto Typed FP entrypoint for programmers instead of Haskell. That'll help drive more adoption for the paradigm because the ecosystem is a lot more approachable and one wouldn't feel overwhelmed to even begin.