You didn't see anything like this 12 years ago, because it simply wasn't possible with just HTML. You had to use a closed source, expensive tool to do it. And 12 years ago, when it was being done by people like Joshua Davies, Manny Tan, that guy behind assembler.org, they were doing something very, very important: they were bringing computer art to every living room, they were exploring generative algorithmic art and they were advancing the idea of what could be done with tech of that time. It was pretty important shit.
This code is useful in a lot of practical ways - games coming to mind almost instantly. But not everything has to be practical. Something can just be beautiful. I find this to be beautiful and fun.
HN needs less posts like yours. It used to not have them. I am glad to see some positive in other comments in this thread, but your comment in particular is relatively useless. Particularly after you admit to using Windows in 2013. That's like someone driving a Ford telling me what a waste of metal a work of art like a Lamborghini is.