I thought Elm was very much about web development. And Elixir is too in some ways. Both Scala and F# have a lot going on in the data space. Scala more so than F#. Standard ML is exciting because it's not big. And probably a better choice for understanding the fundamentals but Scala or F3 for something serious? This is just my best guess. Actually that reminds me of a very nice course in Standard ML from the University of Washington on Coursera, but it's not a book.
Are you talking about the Programming Languages course on Coursera? I intend to do it someday. The first few videos seemed very nice, indeed.
Phoenix is about webdev, but Nerve is not. There was a recent thread on HN on using Elixir for Machine Learning. Maybe look into that? Elixir is just very pretty in my eyes.
Scala is dominant in big data for almost a decade now. Haven't heard that about F#.
Yes, the programming languages course on Coursera! Yes, you're right, Scala is a lot more prevalent mostly because of Spark. I work on Spark occasionally but mostly use pySpark. But I'm fascinated by the world of functional programming. I think I tried setting up Elixir on my Mac a couple of years ago and it didn't work for some reasons and I almost forgot about it after that. I'm a bit interested in F# as a lot of finance companies use it. It's not that popular. I learned a bit from a Udemy course and I really liked the language even thought I'm not a fan of Microsoft. And it works perfectly on Macs! :)