The parent post as more about component based styling then css-in-js.

As for css-in-js, there isn't much of an advantage to using it vs importing sass files as scoped.

With Sass you get:

- Familiare Syntax

- Avoids inline styles

- All benefits of the Sass community

vs with css-in-js you primarily gain:

- Dynamic and regular styles together

- One less compiler dependency

- Benefits of full JS for style generation

So I think this really depends on the project and your preference, I don't think there's a massive benefit either way.