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

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!