Top article, kudos! applied some of these techniques previously, and they do matter a lot. thing is, when you learn/teach JS there is usually limited time left to talk these topics, and they are essential more than it seems.
the whole point of cooperative multitasking is to yield now and then (back to the runner), so that it can process the drawing. Besides, at 60fps there's so much that can be computed once every N frames, and the eye does not see it, the animation flows.
It becomes even more interesting when webgpu is involved, but the CSS animator is indeed very fast.
note: some recent work of mine (newskool digital flyer sites) -> bsf.hmsu.org // nouveauxhivers.dub4powder.xyz