I found it refreshing to read about the migration away from jQuery that GitHub successfully completed recently: Removing jQuery from GitHub.com frontend.
They did it incrementally for obvious reasons, leveraging modern browsers and (lots) of polyfills. It seems they haven't used Babel at all.
Two paragraphs of the article stuck with me the most:
Progressive enhancement is a concept at least ten years old and I'm glad more and more people are keeping it in mind.