2015 was about the last year you could get away with publishing an interactive graphic with a fixed width — this made it harder do really creative/original work.
> another edit: I also believe one reason that this visualization is good is because there's no build process in the JS. The author clearly just edits the code and refreshes the browser. You need that kind of fast edit-view loop to make good visualizations.
You can go a step further and reload code without refreshing the page. This makes it even easier to make the sort of fiddly tweaks that visualizations require while avoid change blindness.