CSS is not a paradigm. Whatever workflow you have for styling your pages and apps, it's all CSS in the end.
It also doesn't matter if it's all CSS in the end. At one particular end it's all manipulating assembly instructions, but I wouldn't call styling pages writing assembly. That is to say the underlying model or paradigm (styling in this case) doesn't really matter if you build an abstraction on top of it that hides that paradigm.
The phrase "shifting away" from CSS is what I was addressing my initial comment towards, and I don't believe that using a paradigm on top of CSS would constitute a shift away from CSS... you're still using plenty of CSS rules whether you use styled-components, modules, SCSS, etc.
The fact that it's possible to define layout and styling using just style properties is the giveaway.