Earlier quoted context omitted.
Javascript has a terrible embarrassment of a standard library. Things that should just be baked into the language are not, which has lead to attempts to rectify that shortcoming, like jQuery, Underscore and LoDash. Because this standard library isn't implemented in the browser itself, where it belongs, people have gotten upset about downloading a few hundred kbs of a general purpose utility library, and instead reimp…
And not just in javascript. HTML is largely the culprit too. A lot is done in javascript that HTML should really handle. For instance why can't we just add a URL attribute to an input to provide autocomplete and validation. It is such a common scenario there shouldn't be a need for a javascript framework to provide that. Same thing with responsive design. But these technologies are stuck in the 90s and barely evolve…
You can. is part of HTML5[0].
Of course, support may not be universal[1], which is why you will probably always have to use javascript if cross-compatibility matters.