I found the "a single div" site to be interesting and great inspiration from time to time, so I shared it here. I feel like, it usually benefits the community if we see and discuss old projects from modern web development eyes.
These are fun little CSS Art and I agree this might have become a niche topic but that does not mean it's lost. These little graphics in the early days is what pulled me towards learning CSS even better and I hope discussing this now, today, would help new web developers get excited for CSS as it did for me back then.
It seems like you have nothing to discuss regarding the original link and it's obvious from other comments that people still find this interesting contradicting your whole point.