JS performance isn't that important for most tiny apps. It's client side code and distributed. If JS performance were important, someone would write a jQuery

JS performance isn't that important for most tiny apps. It's client side code and distributed. If JS performance were important, someone would write a jQuery -> js compiler and produced compiled js as output. But they don't do that, because once you benchmark the code, you find out that DOM is very slow, as johnbender mentioned. I'm still used to hacking in vanilla JS, but when I want to write something longer than a hundred lines, I load jQuery. It's the only sane tool to reduce code size. It does it in a pretty disciplined, lisp-y way, too. It's liberal use of the $(selector).f(x).g(y).h(z) style, which applies the function to the previous result, which is a collection, helps you code at a higher level of abstraction. No more loop structures! It's not time to sunset jQuery: it's time to put more support for jQuery style functions into ECMAScript, so you can get better performance though parallelization, lazy evaluation, etc.