I would agree with your comment, but the author is not claiming to be reimplementing jQuery in 10 lines of code. He's merely providing a way to benefit from the

I would agree with your comment, but the author is not claiming to be reimplementing jQuery in 10 lines of code. He's merely providing a way to benefit from the syntactic sugar ($) to avoid using the verbose vanilla JS API (document.querySelectorAll) and solve the issue of NodeList not supporting the functionality available on Arrays (forEach, map, etc), which doesn't make any sense in the first place.