I know, i know, it's awesome. But, unless it's specifically to make a point regarding the absurdity of today's web (such as eg demonstrating CSS Turing completeness), I can't help finding such hacks sad, because it just blends in to demonstrate how far we've striven from what once was a vision for a rational media architecture with a dedicated vector graphic format.
SVG is an incredible and underrated format. You can create illustrations in svg with modern graphics tools, yet still hack and animate them with css and js. And CSS Houdini is a really exciting development, too.
Some things about the web platform are frustrating for sure, but this sort of project isn’t any kind of statement on the effort required to build modern web graphics and illustrations because you’d never approach it this way. It’s just a fun puzzle for the artist, and every tech and medium has examples of this sort of thing.