That's a valuable addition, but it's unfortunate that it arrived late. These days, functional CSS http://minid.net/2019/04/07/the-css-utilitarian-methodology/ is gaining popularity due to its effectiveness in reducing the need for excessive nesting of classes and unwieldy CSS files.
Functional/atomic css is great. But there are many use cases for composing and refactoring them into aggregates. Nested css can help you for tgese cases.
The more you rely on CSS to change the visuals based on situations, the worst to main in the future. It's an option, that's good, but for me it's been years that I don't go back to that anymore.
