I read some of his explanation about constructors and he explained it well compared to other available resources. In fact, I think it is worth reading as Vanilla JS will pave the way to better understanding of JS frameworks and libraries.
The issue it was published in 2011, so is it still worth reading? Is it still relevant? If not any other detailed guide?
As I said the book is good, its author is top-notch (MIT graduate), yes it’s worth reading, but you won’t be done when you finish it, you’ll have to resort to other resources for ES6+ features.
Core JS has not changed, it’s still prototypal inheritance based and the
constructor are just syntactic sugar around it.
Know that there’s no one true book/resource to learn it all in this field.You’ll have to sift through seemingly endless garbage of info and musings from self-proclaimed authors.