I agree, JavaScript the Good Parts was written in a time when there essentially was no ecosystem in Javascript to speak of, so it was by definition focused on n

I agree, JavaScript the Good Parts was written in a time when there essentially was no ecosystem in Javascript to speak of, so it was by definition focused on nothing but the language. In 2019 JavaScript comes as part of a much more developed (and useful!) ecosystem that is completely tied in with tools such as Babel and Webpack and the alternatives mentioned. Even if you don't use or want to use any particular one of them, knowledge of all of them, at least what they do, is more or less essential to work in modern JavaScript to understand how the ecosystem fits together and how most projects out there use the language.