We're migrating to styled-components at my current company. It's nice for abstracting components -- either into shared libraries or separate micro-clients that are composed together at runtime.

In those scenarios, there are a few benefits: (a) no worries about accidentally trampling on someone else's styles, or styles from elsewhere overriding your styles; (b) build configuration is simpler; and (c) no worries about how CSS/SCSS is referenced/loaded - all references are handled in plain JS with no special loaders or anything.

I wouldn't use it everywhere (I've used other approaches that have worked just fine), but for some scenarios it makes sense.