That's a nonsense statement. There is no technical achievement, it's no breakthrough in any relevant technical sense. Sorry to get technical, but you called it.
I'm not dismissing the demo, mind. It's a great feat of engineering and its main achievement, that is creative, surely thrives from a technical esthetic.
Using system libraries has to be put into perspective, for sure. The common wisdom (in sizecoding at least) is that creativity thrives from constraints. Necessarily then, one has to be aware of the constraints.
One might say having to write in .js is extreme masochism, so the criticizm about .dlls is just one side of the equation. Browser bugs and all that. no, thanks.
Too often you have to read how a sizecoded demo uses a ton of system libraries or whatever, completely dismissing the technical achievement.