To keep in mind, à la longue, the best CSS is probably no CSS. Does a user really need all these buttons and dropdowns, modals and scrollable containers, or do they need only an input and a container rendering a few paragraphs, an image, a video/audio, possibly a 3D model.

I see no problem if instead of using all these web sites/applications with such a plethora of visual and experience spam, I just have a single input box connected to an agent through which I interact with them all, letting the APIs settle in the background.