I left scala in 2014 because pure functional scala was clearly a dead-end (in industry) and why else would I use it, but in 2020, ZIO + Scalajs is making me want to try pure FP again (for industry). (I'm a ClojureScript programmer)
I wouldn't call pure functional Scala a dead-end, but it's definitely a niche that not everyone will be comfortable with. For those that enjoy it it works great, but this book is intended to promote a style of programming that is perhaps more approachable to programmers coming from outside the Scala ecosystem.
Scala.js amazing. It just works. I've picked it up after multiple years of non-use and it everything worked perfectly with no surprises. I don't cover it in this book, but might write about it in another book in future!
