>...what we call web frameworks are transforming from runtime libraries into optimizing compilers.

I took that to mean that the frameworks are doing the optimization. But the article doesn't give examples of the frameworks. The only examples of code transforming optimizations are Uglify and Babel. So I thought maybe these were the things the author has in mind and not actual frameworks. I was genuinely confused and prefaced with the aside about pedantry because questioning these kinds of semantics can come across as pedantic.

The second half of my comment stands regardless.